Mathew Kevin


A “central heating thermostat” – is just the same normal thermostat that is used to control a central heating system. In USA, the two most commonly used type of central heating systems are a boiler or a furnace. A central heating system produces heat at one point (usually setup in the basement area or a furnace room) and distributes heat to the whole building by forced air through duct works (in the case of a furnace), or as hot water/steam through pipes (in the case of a boiler). A thermostat that is compatible with a central heating system can be called – a central heating thermostat; that is a thermostat compatible for a boiler system or a central furnace.

As we’ve mentioned in our other guides, about 90% of homes in USA is using heating systems like a boiler or a furnace or a heat pump. When a central heating system is combined with other systems (like ducts/pipes for heat distribution, thermostats for temperature control, cooling coils) – it forms a complete HVAC system. We’ve published guides featuring Central Furnace Thermostats and Central Boiler Thermostats – both guides covering smart, WiFi and programmable thermostats compatible for central heating systems.

Thermostats for Central Heating Furnace

A furnace based central heating system mainly involves a central furnace setup in one point, and the heat produced in the furnace is distributed through ducts as warm air. Natural gas is the commonly used energy source in a central furnace. In USA, around 49% of homes are powered by natural gas based central heating systems (source). Other than natural gas, Electricity based heating systems (nearly 33% of households), fuel oils (6%) , propane/LPG (5%), wood (2%) are also used as energy source in a central furnace.

The heat produced in a furnace is used to heat the air in a heat exchanger. The warm air is then distributed with help of blowers (forced air), through ducts which are passing through each and every room. A central furnace is relatively cost effective heating system, compared to boiler or other systems.

Thermostats for Boiler Heating Systems

Boilers – as the name implies, uses hot water distribution through pipes installed in different rooms. A boiler unit is setup in one point (usually in the basement) and water is heated to a desired temperature (not really till the boiling point). The hot water is then passed through radiators and pipes installed through out different rooms, where they release heat from hot water while passing. Most commonly, boilers use “natural gas” as fuel source. However, heating oils, electricity, propane/LPG, wood are also used as fuel sources to produce heat.

Boilers are costly to install compared to central furnace heating systems. The reason for high cost is pipes & radiators which have high material cost compared to setting up air ducts. The key advantage of a boiler is the ease of setting up “zoned systems” where each individual rooms can be set as unique zones – which can be controlled using thermostats installed in each rooms.  Central furnace based heating systems are not ideal for setting up zoned systems.

Central Heating Thermostat Types

A handful of choices are available as central heating thermostats – which can be WiFi/Wireless heating thermostats, or smart thermostats, or digital programmable thermostats for central heating systems. Out of these 3 models, smart thermostats are the most modern type with advanced features like self learning, energy savings, internet based control using smartphones, geo-fencing and a lot more. If you’re price conscious, go for a normal digital programmable heating thermostat, which would be budget friendly.

WiFi/Wireless Central Heating Thermostats

We’re living in an “internet connected” era and most people prefer connected smart devices these days. Internet connected devices often provide us with great convenience as they can be controlled from anywhere using smart phone apps. Most of the new generation thermostats like Nest, Ecobee, Emerson Sensi, Honeywell RTH9585WF  – are all WiFi enabled thermostats suitable for any central heating systems (be it a boiler or a furnace). All these wireless central heating thermostats can be connected to your home WiFi and they can controlled from anywhere using the respective mobile apps.

Out of the 4 models listed above, Nest, Ecobee and Sensit ST75 are “smart thermostats” with high end features like energy savings, auto programming, geo-fencing and other useful features. Let’s go through all of them in a nutshell.

#1 Ecobee 4 and Ecobee 3 Lite

We’ve covered full review of Ecobee 4 and Ecobee 3 Lite – where we have detailed features, compatibility, comparison between the two models and a lot other useful information. Ecobee 4 is the full featured model with built in Amazon Alexa, and comes with an extra room sensor to setup zoned system (to manage any hot/cold spots in your home). Ecobee 3 Lite – is the budget model central heating thermostat, which is basically a trimmed down version of ECobee 4. There is no built in Amazon Alexa and no room sensor is provided with Ecobee 3 Lite.


For Boiler – Both ecobee models are compatible with central heating boilers. They support 2H/2C – Two stages of heating and Two stages of forced air cooling.

For Furnace – Both ecobee models support central furnace heating systems. They are compatible with single stage systems and multi stage systems (upto 2H/2C – Two stages of heating/cooling)

Note: We’ve covered compatibility of all popular thermostat models in our guide.

#2 Nest 3rd Gen and Nest E

Nest 3rd Gen is the full featured model with “self learning”, energy savings, geo fencing and a lot other smart features. Nest E is the budget model with differences in build quality. The key difference between Nest 3rd Gen and Nest E is in compatibility. Nest 3rd Gen is compatible with 90% of HVAC systems, where as Nest E is compatible with only about 80% of HVAC systems in use.

We’ve reviewed Nest 3rd Gen and Nest E – in our comprehensive guide covering all aspects & comparisons. Read through our guide, if you’ve Nest models in your mind.


For Boilers – Nest 3rd Gen supports upto 2H/2C (two stages of heating/cooling). Nest 3rd Gen also supports dual transformer configuration. Nest E supports upto 2H/1C only (two stages of heating and one stage of cooling). Nest E doesn’t support dual transformer configuration.

For Furnaces – Nest 3rd Gen supports upto 2H/3C (two stages of heating and three stages of cooling). Nest E supports only upto 2H/1C (two stages of heating and one stage of cooling)

#3 Emerson Sensi ST75

Emerson Sensi ST75 is a value for money WiFi central heating thermostat with lots of useful features like energy savings, voice control, geo-fencing, internet control and more. The only feature Sensi ST75 lacks is “self learning” which is commonly found in smart thermostats like Nest and Ecobee.


For Boilers & Furnaces – Sensi ST75 supports upto 2H/2C – two stages of heating and two stages of cooling for both boilers and furnaces.

#4 Honeywell RTH9585WF

Honeywell is still one of the market leader in thermostats, as they have models covering different budgets and different types of HVAC systems. “Honeywell RTH9585WF” – is one of the best selling WiFi central heating thermostat model suitable for central furnace and boiler based HVAC systems. This model comes with a big, color, touch screen display – where the color of touchscreen interface can be changed to suit your room interiors. The model also has voice control enabled – and is compatible with Amazon Alexa, Apple HomeKit, Google Home and other smart home hubs.


For Boilers & Furnace – Honeywell RTH9585WF supports upto 2H/2C – that is 2 stages of heating and 2 stages of cooling. Fan is supported for electric furnace models. Other accessories like humidifiers and ventilators are not supported.

In USA, about 90% of homes is powered by a central heating/cooling system like a central furnace or a boiler or a heat pump based system. We write about boiler thermostats in this guide, which are thermostats for controlling central boiler units. A boiler is basically a specially designed water heater – which distributes heat through hot water, while systems like a central furnace distribute heat through warm air. Water is heated in a special chamber of the boiler (which is usually powered by gas or fuel oil) and is then distributed to different rooms of the home via radiators or other heat distribution systems installed. A boiler thermostat helps in controlling the boiler operation, thus maintaining a proper set temperature inside the home.

As I noted above, there are different types of boiler systems like gas-fired boiler, steam boiler, and fuel oil based boiler. Out of these 3 types, gas-fired boiler is the most common one in USA, just like the central furnace based heating systems. You may find steam boilers in some older home constructions, but they are being replaced eventually. Fuel oil based boilers are not used in US homes due to many reasons like foul smell, and efficiency problems. All thermostat models reviewed below are suited to use as a gas boiler thermostat – be it a smart thermostat or a WiFi/Wireless boiler thermostat model or just a normal programmable thermostat variant.

We are here to help you learn more about boiler thermostat models, to find the right one that best fits your boiler heating system.

Smart Boiler Thermostats

Smart Thermostats” are technologically superior, modern, internet connected thermostats which can save energy like no other thermostats. A smart thermostat can save energy in the range of 10% to a max of 23% (under ideal conditions) annually. Apart from energy savings, smart thermostats are built with high end features like control from anywhere using smartphones, self learning (auto scheduling and auto programming), voice control, geo fencing (turning your boiler ON/OFF based on homeowner’s location). Let’s see the best smart boiler thermostats available.

#1 Ecobee 4 & Ecobee 3 Lite

Ecobee smart thermostats are our #1 choice as boiler thermostat. Ecobee has two models in the market, Ecobee 4 – the full featured model and Ecobee 3 Lite – the budget model. Both Ecobee 4 and Ecobee 3 Lite supports 2 stages of heating and cooling (2H/2C) for boilers. They also support 2 stages of forced air cooling (which is known as 2 transformer configuration in boilers). Ecobee thermostats works well with gas boilers and they are a good choice as gas boiler thermostat.

Out of the 2 models, Ecobee 4 – is the full featured model with high end features like built in Amazon Alexa (for voice control) , self learning (auto programming/scheduling), geo-fencing, smart phone based control via internet, and above all energy savings upto 23% (as claimed by Ecobee company). Ecobee 4 also comes with an extra room sensor to setup zoned heating/cooling and manage any hot/cold spots in your home.

You may read our full review of Ecobee Smart Thermostat – comparing Ecobee 4 vs Ecobee 3 Lite. You will get to know complete features and compatibility with your HVAC system.

Ecobee 3 Lite – is the budget model, which is basically a trimmed down version of Ecobee 4. The budget model has all important features of Ecobee 4, except that it has no built in Alexa (you’ve to purchase Alexa device separately to enable voice control in Ecobee 3 Lite), and there is no extra room sensor provided (you can buy room sensors separately). Finally, take note that the full featured model Ecobee 4 is compatible with more types of heating/cooling (HVAC) systems. Ecobee 3 Lite may not be compatible with central heating systems having 3 or 4 stages. Also, Ecobee 3 Lite doesn’t support any accessories like humidifier or dehumdifiers.

Note: We’ve created a guide featuring compatibility of different thermostat models – where we detail compatibility with different stages, accessories, aux systems etc.

#2 Nest 3rd Gen and Nest E

Our #2 choice is Nest 3rd Gen and Nest E. In our opinion, Nest smart thermostats are equally good as Ecobee models. They both can be #1 choice alike. But we chose Ecobee as #1 for the extra room sensor (that comes with Ecobee 4) and the alternative option for a C wire/common wire (if you don’t have c-wire, Ecobee provides a PEN – power extender kit which can be used to solve the C – wire requirement).  Just like Ecobee, Nest has two models namely Nest 3rd Gen and Nest E. The full featured model Nest 3rd Gen thermostat has more features, higher compatibility and better build quality compared to the budget model Nest E. Nest thermostats also goes well as a gas boiler thermostat, and can be used perfectly for your gas boilers.

Nest 3rd Gen – “Learning Thermostat” – as Nest calls it officially is a self learning thermostat which programs itself by learning lifestyle patterns of homeowner. It also has advanced features like “geo-fencing”, internet connected control using smartphones, vacation schedules, energy reports, and many other features. The key highlight is “energy savings” – where Nest claims upto 13% of annual savings with their thermostats.

If you’re interested in Nest thermostat, you should read our review of Nest 3rd Gen vs Nest E – where we compare both models with features and compatibility.

Nest E – the budget model thermostat is a trimmed down version of full featured model. The primary difference being lesser compatibility (Nest E is not compatible beyond 2H/1C – 2 stages of heating and 1 stage of cooling) and build quality (Nest E is built of plastic materials). Apart from this difference, all high end features of a smart thermostat like “self learning”, controlling via smartphones, energy savings, geo-fencing and other features are common for both Nest models.

Nest – Compatibility as a boiler thermostat

Nest 3rd Gen is compatible upto 2H/2C – Two stages of heating and Two stages of cooling for boilers. As a boiler thermostat, Nest 3rd Gen model supports “dual transformer configuration” – where there is more than one R wire.

Nest E is compatible only upto 2H/1C – Two stages if heating and One stage if cooling as a boiler thermostat. Nest E does not support dual transformer configuration.

You may read through our thermostat compatibility checking guide to learn more Nest Thermostat compatibility with different systems.

Wireless/WiFi – Boiler Thermostats

As we’ve seen, “smart boiler thermostats” come packed with a lot of high end features like “self learning”, geo-fencing, high energy savings, WiFi and internet based control and more. All these features are really useful but they come with high price tag as well. If you’re looking for an affordable modern thermostat, then WiFi enabled boiler thermostats are a good choice. Just like smart thermostats for boilers, these WiFi enabled models are good to use as a gas boiler thermostat or as an oil boiler thermostat.

These models will have all those “essential new generation features” like voice control, WiFi connectivity, touch screen, smart home hub integrations, programming/scheduling via mobile apps and a lot other useful features, except high end ones like “self learning” or “auto programming”. The energy saving rate wouldn’t be as high as a smart thermostat but you can expect anything in between 5% and 10%. The key highlight is affordable price compared to a smart thermostat model.

#3 Honeywell RTH9585WF – WiFi Boiler Thermostat

When it comes to WiFi thermostat models, “Honeywell RTH9585WF” is the #1 choice anyone should consider. This model from Honeywell is an upgraded version its best seller – “Honeywell RTH9580WF” – which once ruled as the #1 WiFi thermostat for boilers or other central heating systems.

Honeywell RTH9585WF – is a WiFi enabled, programmable thermostat with color touch screen. One highlight of this model is “different color choices ” available on touchscreen interface, which you can select to match your room interiors. The bigger display & touch screen interface makes it appealing to people who don’t prefer the “minimal display size” of Nest & Ecobee thermostat models.

The key highlight of the model is WiFi based control over internet. You can control this thermostat via internet from anywhere in the world using the mobile app (provided by Honeywell). You can set new schedules or change the existing ones, turn ON/OFF, read current room temperature etc from anywhere. Apart from WiFi based control, this model also supports voice control via Amazon Alexa or other smart home hubs like Apple Homekit, Google Home or another supported smart home device.

Boiler Compatibility

Honeywell RTH9585WF supports boilers upto 2H/2C – that is 2 stages of heating and 2 stages of cooling. This model support boilers with gas, oil or electricity as fuel source. Take note that accessories (like humidifiers, or ventilators) are not supported. Also keep in mind, this model requires a “C-wire” in your home wiring setup.

#4 Emerson Sensi ST75

The next best choice in WiFi enabled boiler thermostat models is “Emerson Sensi ST75” – which is a wireless/WiFi thermostat from home automation giant Emerson. We’ve reviewed Emerson Sensi ST75 in detail, and we believe this thermostat is a great choice for any of the common boiler types used in US households.

You’ve to check compatibility of a thermostat with your homes HVAC system, before you buy the thermostat. We believe checking thermostat compatibility is very important for anyone buying a new thermostat or replacing an old model. If you don’t check thermostat compatibility, you might end up purchasing the wrong model. We’ve created a comprehensive thermostat compatibility guide covering almost all the current best selling thermostat models.

Compatibility Guide for Smart Thermostats

Let’s begin with smart thermostats as they’re the best selling models currently. Most people prefer to use smart thermostats these days as they are self learning, saves energy and can be controlled from anywhere via internet.

Ecobee 4 & Ecobee 3 Lite

We’ve published a dedicated review of Ecobee 4 & Ecobee 3 Lite covering all aspects including compatibility. If you’re considering Ecobee thermostat, please go through our guide and get informed.

Ecobee Thermostat Compatibility

The table below explains compatibility of Ecobee 4 and Ecobee 3 Lite with a wide variety of heating/cooling systems out there.

Nest 3rd Gen & Nest E

Nest thermostats are compatible with a wide range of HVAC systems, especially the Nest 3rd Generation Learning Thermostat. The table below explains Nest thermostat compatibility (Nest 3rd Gen and Nest E) with different types of heating/cooling systems. We’ve covered Nest 3rd Gen and Nest E thermostats in our complete review and comparison guide.

Emerson Sensi ST75

We’ve covered Emerson Sensi ST75 in a detailed review. The table below explains compatibility of Emerson Sensi ST75 with different types of HVAC systems.

Honeywell RTH9585WF

This model from Honeywell, RTH9585WF is one of the best selling WiFi thermostat models out there. We’ve listed the complete compatibility of Honeywell RTH9585 thermostat model in the table below.

Compatibility for Line Voltage Thermostats

Thermostats are basically for two types of systems – low voltage and line voltage. Thermostats designed for line voltage systems (like baseboard heater, convectors etc) are not compatible to be used with low voltage systems (like central furnace, heat pumps, boilers etc). Similarly, thermostats designed for low voltage systems can not be used with line voltage systems as well. You’ve to identify your home heating system first (if it’s a low voltage or line voltage system) before choosing your thermostat.

In USA, 90% of homes are using low voltage systems like a central furnace or a heat pump or a boiler as their heating/cooling system. Only about 10% of homes are using line voltage systems like a baseboard heater or a forced fan heater or a convector or a radiant ceiling heater.

MySa – Smart Line Voltage Thermostat

MySa is a smart line voltage thermostat compatible with all commonly used high voltage systems. Complete compatibility is explained in the table below.

Winding up!

We’ve covered almost all best selling thermostat models in our comprehensive thermostat compatibility guide. We will be adding newer models in coming days. If we’ve missed an important model, please comment here. We shall add them shortly.

When you hear “smart thermostat” the first names that comes to mind is either Nest or Ecobee.  Nest enjoyed an unrivaled market leadership in smart thermostats for a long period as they were the pioneers. After a few years, Ecobee came with a couple of outstanding smart thermostat models to take share from Nest. Now Emerson has released a really good smart thermostat model – ST75 under its “sensi” series of thermostats.  Emerson is a very reputed company manufacturing automation products for years and has a legacy of 128 years in business. Let’s go deep to know more about Emerson Sensi – ST75 – Smart Thermostat.

Emerson Sensi – ST75 Smart Thermostat 

The key highlight about Emerson Sensi ST75 is that it offers all essential features of a smart thermostat on a budget price. Sensi ST75 offers all major features of a smart thermostat like #energy savings – where energy & money is saved by running  the hvac system at max efficiency, #geo-fencing – where the location of homeowners are tracked and rooms are preheated when the homeowner nears home from office or far away places, #voice control enabled and works with Amazon Alexa, Apple HomeKit and Google Assistant. Apart from this 7 day scheduling and smartphone app based control (using WiFi and internet) are provided just as good as Nest & Ecobee.

The main drawback is lack of “self learning” unlike a Nest or Ecobee model. You’ve to program the thermostat yourself based on your preferences (Nest & Ecobee are self learning and they program themselves automatically). Another key point is size of thermostat and display – which is definitely bigger & bulky than Nest & Ecobee (which are sleek and round). But bigger display has its own advantages (easy to setup and program) and some homeowners really prefer thermostats with bigger display.

Sensi ST75 Compatibility Guide

The key fact to check before buying any thermostat is compatibility with your home HVAC system. You should be informed that some thermostats do not support certain HVAC system types. Let’s see the compatibility guide for Emerson Sensi ST75 thermostat.

Central Furnace/Boilers – Supports upto 2 stages of Heating (W/E, W2) and 2 stage of Cooling (Y, Y2)

Heat Pumps – Supports heat pumps and heat pumps with auxiliary/emergency heating (O/B, W/E, W2)

Fan – (G) and Power – (C, RH, RC)

C-Wire Requirement – “C Wire” or common wire is required for this thermostat. If your home wiring doesn’t have c-wire, Sensi ST75 can not be used in your home.

Note: Sensi has a compatibility checker tool in their website. Please make use of it and check compatibility.

Highlight Features

Energy Savings – is the key highlight feature of Sensi ST75, just like Nest and Ecobee. Though Nest and Ecobee declared their energy savings to be 13% and 23% respectively, Sensi has not made any official number based claims. We can assume it to less than Nest (13%) for the time being.

Geofencing – is a smart feature in Nest and Ecobee. Now Sensi also adds the same! Geofencing is nothing but tracking a homeowner using his mobile phone and adjusting the home temperature after he leaves and before he arrives.

Voice Control & Smart Hub Integrations – Compatible with Amazon Alexa, Google Assistant, Wink, Apple Homekit

Flexible Scheduling – Set the program using the thermostat touch screen or using the mobile app. 7 day programmable and set a unique schedule for each day that fits your lifestyle.

Wrap Up!

Sensi ST75 is a budget friendly, value for money thermostat that suits any homeowner. Two key points against this models is lack of “self learning” and the inability to interface extra room sensors. Both Nest and Ecobee can be interfaced with extra room sensors to mange any cold spots in your home. Apart from that, Sensi ST75 is a great choice.

We used to live in a “wired” world before and now we are moving towards a “wireless” world. The internet has changed our world like none has ever dreamed some 15 years ago. We live in a “highly connected” world now, that you can control your home in Washington DC sitting in Miami beach! The first internet connected wireless thermostat was Nest smart thermostat which was released in 2011. Later Ecobee and Honeywell came up with WiFi thermostat models in market. In this guide, we review wireless thermostats or WiFi enabled thermostats which could be controlled over internet using mobile apps.

Why Go for a WiFi Thermostat?

WiFi Thermostat benefits
Benefits of WiFi Thermostat

#Control from anywhere – A WiFi thermostat can be controlled through internet from anywhere in the world.  Set/change temperature, turn ON/OFF, set new program/schedule – you can do it all while you’re away.

#Accurate Weather Prediction – They fetch local weather conditions from internet and sets program/gives alerts.

#Everything on Mobile Apps – Get temperature/humidity levels, energy usage reports, alert messages all on your mobile app.

#Geo-fencing – Smart wifi thermostat models have geo-fencing feature which tracks a home owner and automatically adjust temperature when owner nears home (from office or an away place)

Wireless/WiFi enabled models are available for all the different types of thermostats – be it for a furnace thermostat or a heat pump thermostat or a boiler thermostat or even the electricity powered line voltage or baseboard heater thermostat has WiFi enabled variants available. Let’s see the best wireless/wifi thermostat models in each category!

Wireless/WiFi Smart Thermostats

Let’s begin with smart thermostats – which are self learning and programs itself automatically. Smart thermostats are the innovative & high end thermostat models available in market today. All smart thermostat models have wireless feature and they can be controlled via your home WiFi. We’ve shortlisted 3 best WiFi smart thermostat models for you to choose from.

#1 Ecobee 4 and Ecobee 3 Lite

Ecobee is a new generation home automation company (just like Nest), and they have two flasgship smart thermostat models – Ecobee 4 and Ecobee 3 Lite. Out of these 2 best selling models, Ecobee 4 is the full featured version with complete features of a smart thermostat. Ecobee 3 Lite is a budget model (priced affordably) and is basically a trimmed down version of Ecobee 4. We’ve reviewed both thermostats detailed in our article – Ecobee Smart Thermostat Review.

Ecobee 4 and Ecobee 3 Lite – both models are wireless and home WiFi compatible. You can connect them to your home WiFi network and control them using the Ecobee mobile app. Ecobee4 is a wireless room sensor thermostat, as it comes with an extra room sensor (which is interfaced wireless to thermostat).

A quick review of important technical specs about wireless/internet connectivity of Ecobee 4 and Ecobee 3 lite is furnished below. If you’ve Ecobee WiFi thermostat in mind, you’d get detailed tech spec from our review of Ecobee thermostats.

#2 Nest 3rd Gen and Nest E

Nest is the pioneer in smart thermostat models and they have Nest 3rd Gen (the full featured model) and Nest E (the budget friendly model). Nest & Ecobee are equally competent thermostat models, and you can choose any one after reading through individual reviews. We’ve covered Nest 3rd Gen and Nest E in detail – where we cover full features of both Nest thermostat models, compatibility and comparison between Nest E and Nest 3rd Gen.

Both Nest models – Nest E and Nest 3rd Gen are wireless/WiFi smart thermostats. Unlike Ecobee4, the full featured Nest 3rd Gen doesn’t come with a wireless room sensor. However, you can purchase additional wireless room sensors from Nest and interface it with your thermostat. You can read such technical details by following our individual reviews of Nest and Ecobee.

A quick nutshell of important tech specs regarding WiFi and wireless connectivity of Nest E and Nest 3rd Gen is furnished below. If you’re seriously considering Nest wifi thermostats, we encourage you to go through our detailed review of Nest thermostats.

#3 Emerson Sensi – ST75

Sensi ST75 is an affordable smart thermostat with all essential features except “self learning” or the auto programming feature. We’ve covered review of Sensi ST75 in detail – where you can find full details about its features, HVAC compatibility and much more.

Sensi ST75 is a WiFi thermostat which houses all the necessary and essential features of a modern day thermostat but it lacks the supreme “self learning” of smart thermostats. We’ve put together a table showing all the important tech spec regarding wireless/internet connectivity of sensi ST75.  If you’ve Sensi ST75 in mind, we recommend you read our full review of Emerson Sensi ST75 and make your mind.

Wireless/ WiFi Digital Programmable Thermostats

Smart thermostats makes our life so easier with its high end features & functions, but they are high priced. If you don’t have the budget for a smart wireless thermostat, choose an affordable wireless/WiFi digital programmable thermostat. These are basically the popular 7 Day or 5 Day programmable digital thermostats equipped with wireless and WiFi capability. You can control these thermostats via internet using your mobile phones (using the apps installed) – like you can turn ON/OFF, change temperature settings, change program schedule etc.

We’ve shortlisted 3 best wireless/WiFi enabled digital programmable thermostats for you ti choose from. Read through our list and see the highlights of each model.

#1 Honeywell RTH9585WF – WiFi 7 Day Programmable Thermostat

Honeywell is still a leader in thermostat market (they enjoyed unchallenged position until the arrival of Nest and Ecobee), though they are only 3rd or 4th in smart thermostat rankings (Honeywell has a smart thermostat model named Lyric – which is not very popular compared to Nest and Ecobee). RTH9585WF – is a WiFi 7 Day programmable thermostat from Honeywell with color touch screen display and Alexa enabled voice control.

#2 Honeywell RTH6580WF – Budget Friendly WiFi Programmable Thermostat

RTH6580WF is an economical, budget friendly wireless programmable thermostat from Honeywell. This is one of the best selling and popular thermostat models out there with almost all essential features. The key features include Alexa enabled voice control, 7 Day programmable, 4 programming modes, and can be interfaced with smart hubs like Apple Homekit, Google Assistant and Samsung SmartThings.

#3 Emerson Sensi – ST55 – DIY Wireless Thermostat

Sensi ST55 from Emerson is an affordable DIY WiFi thermostat with all essential features. If you can pay a few more bucks, we would advise you to choose the newer version Seni ST75 instead of ST55

Line Voltage- Wireless Thermostat

Line voltage thermostats are used for heating/cooling systems running on line voltage (120 or 240 volts). An example would be baseboard heaters – where direct electricity is converted to heat energy. Only about 10% of homes in America uses line voltage based systems. A majority (that is about 90%) of homes uses low voltage systems like a central furnace or a boiler or heat pump based systems. The key info here is that a line voltage heating/cooling system requires a thermostat that runs on line voltage. You can not use a low voltage thermostat (like Nest or Ecobee or Sensi) with a line voltage heating system. You may read our complete guide on Line Voltage Thermostats to see different wireless/WiFi high voltage thermostat models.

Heat Pump – WiFi Thermostat Models

Heat pumps are common in most of the homes in USA. Some of the homes use heat pumps with auxiliary/emergency heating. If you’ve a heat pump with aux/emergency heating, make sure the thermostat you choose supports the same (be informed some thermostat models doesn’t support auxiliary heating).

Furnace & Boiler – WiFi Thermostat

As we’ve written before, 90% of Americas runs on central furnace or boiler based systems or heat pump based HVAC systems. All these 3 systems are low voltage HVAC systems. We’ve reviewed right thermostat models for each of these systems individually in our guides – say Guide to Choose Furnace Thermostat or our Guide to Choose Boiler Thermostat. We’re listing handpicked wireless thermostat models for furnace & boiler based systems here.

#1 Ecobee 4 & Ecobee 3 Lite – are excellent choice as WiFi thermostat for central furnace based or boiler based systems. They are compatible upto 2 stages of heating.

#2 Nest 3rd Gen & Nest E – are the next best (or as equally best as Ecobee models) choice as WiFi thermostat for furnace/boiler based systems.

Wireless/WiFi Underfloor/Radial Heating Thermostat

If you’re a little curious here, “underfloor heating” is used in homes to heat the floor surface. A heating system (either insulated electric wire based or hydronic/hot water based) is installed under the floor to heat the floors evenly during winter. Underfloor heating systems are common in homes located in places with extreme winter conditions. We’ve reviewed different models of underfloor heating thermostats – and we’ve covered some wireless underfloor heating thermostats as well. We’re listing one of the best wireless thermostat model for underfloor heating below.

Wrap Up!

We believe, you’ve been benefited by reading through our wireless thermostat reviews. Choosing the right thermostat for your home requires intense research, like identifying your current HVAC system, your current wiring type, which type of new thermostat you need and so on. We crafted our website ThermostatGuide – as an authentic resource on thermostats helping people buy the right thermostat. We intend to help you choose the best wireless/WiFi thermostat with this article and we believed we’ve been of help for you in your research.

FAQ - Frequent Questions!

Is my heating/cooling system (HVAC) compatible with WiFi thermostat?

Compatibility of a thermostat varies with different models. Compatibility of Nest is not the same as that of Ecobee or Honeywell. You should read the compatibility specification of the wifi thermostat model you prefer. We’ve clearly written about compatibility in the individual review of each thermostat.

Will my WiFi thermostat work without Internet or WiFi ?

Any WiFi thermostat model will serve its core function – that is controlling your HVAC (heating/cooling) system and regulating temperature without any internet connectivity or an active WiFi connection. They use the already set schedule/program to maintain temperature. An active WiFi connection is only needed when you want to control the thermostat (say change temperature setting or schedule) from an away place over internet (using your mobile phone). Also some advanced features like live weather tracking and geo fencing would need an active WiFi/internet connectivity.

Can I connect WiFi thermostat to Smart Hubs like Alexa, Homekit ?

Most of the best wifi thermostat models like Ecobee4, Ecobee 3 Lite, Nest 3rd Gen, Nest E, Emerson Sensi ST75, Honeywell RTH9585 can be integrated with smart hubs like Amazon Alexa, Google Assistant, Apple Homekit, Amazon Echo etc. Some models are compatible with other smart hubs like Samsung SmartThings, Wink. Integrating with a smart hub enables you to control your thermostat using your voice.

A thermostat is one of the most important device in any home – as it has a key role in making your life comfortable (by regulating the room temperatures) and saving your energy bills. You may already know there are different types of thermostats and not all thermostats are alike. In this article, we write about programmable thermostats – which can be programmed to manage your schedules & lifestyle preferences. A programmable thermostat help save more energy compared to non-programmable or manual thermostats. Let’s see in detail.

Programmable Thermostats – The Intro!

A programmable thermostat gives you more comfort & energy savings compared to non-programmable or manual thermostat models. The key highlight is they can be programmed according to your preferences. Some thermostats are 7 day programmable, while some others are 5 day or 2 day programmable. Smart thermostats are self learning and they program itself automatically (after learning your lifestyle and habits) to give you the best possible comfort and energy savings.

Programming gives you a lot of control on how to regulate your heating/cooling system – for example, you are at work on weekdays and at home (full time)  during week ends. In such a scenario, you can program the thermostat to turn OFF your heating/cooling system during your work hours and on weekends you can set the program to run your heating/cooling system full time. This kind of flexible programming helps to run your heating/cooling system at the best possible efficiency. Most of the programmable thermostats has holiday schedule option which allows you to either turn OFF the heating system or run at the minimal setting to prevent freezing. And that’s how programmable thermostats save more energy and save you more money compared to other models.

How they Save Energy & Money

Programmable thermostats, especially smart thermostats are really good at saving energy & thereby saving money on your wallet. They save energy by following the set program (your schedule & preferences) to run your HVAC system at the best possible efficiency. Smart thermostats can save upto 23% of annual energy usage (compared to ordinary thermostats) and the budget friendly 7 day programmable thermostats can save nearly 10 to 12% of annual energy usage.

How to Choose a Programmable Thermostat

As I wrote before, there are different types of thermostats designed for different types of HVAC systems. In America, 90% of the homes runs on low voltage HVAC systems like a central furnace or a boiler or heat pump based systems. Around 10% homes runs on line voltage systems like baseboard heaters or convection heaters which uses direct electricity to heat your homes. The very first thing to understand is that you can’t use a thermostat designed for line voltage systems (like a baseboard heater) with a low voltage HVAC system like a central furnace (and vice versa). So there are low voltage thermostats designed for low voltage systems and line voltage thermostats designed for line voltage systems.

In this article, we deal with low voltage thermostats only! We’ve reviewed programmable line voltage thermostats in our previously published guide.  Let’s see some important things to consider before choosing a programmable thermostat.

  • Low Voltage or Line Voltage – if you’re replacing an old thermostat, first identify if your old thermostat is low voltage or line voltage and buy your new thermostat accordingly. If you’re buying a thermostat for your newly installed HVAC system, first identify which type of thermostat (line voltage or low voltage) is suitable for your new heating/cooling system.
  • Type of HVAC System – The first step is identifying if your system is low voltage or line voltage. The second step is identifying your HVAC (heating/cooling system) type. As I said before, 90% of America is running on central furnace or heat pump based systems. The key point here is that a particular thermostat model may not be compatible with all types of HVAC systems. You’ve to identify your HVAC type and check if the thermostat model you consider is compatible with your HVAC system.
  • Single Stage or Multi Stage – A majority of homes in America is running on single stage HVAC systems. However, there are homes which uses 2 stage or even 3 stage heating/cooling systems. In the case of heat pumps, some homes are using single stage heat pumps only while a majority of homes use an auxiliary heating system along with heat pump. The key here is some thermostats support only single stage systems whereas some other models support 2 stage or 3 stage systems. You’ve to understand your system type and buy the thermostat accordingly.

Best Programmable Thermostat – Our Reviews!

We’ve seen the benefits of programmable thermostats – like how they save energy, how they give you best possible comfort and how they save you money. We’ve also seen how to choose a programmable thermostat wisely that suits your HVAC system. Now lets see some of the best programmable thermostat models in our world right now!

Smart Programmable Thermostats

Smart thermostats are basically programmable thermostats with “smart” capabilities & features built into it. They are really “smart” that you don’t need to program them manually by entering your schedule. Smart thermostats program itself automatically by learning your living habits & patterns. After installation, a smart thermostat starts to learn patterns of your lifestyle like when you come home, when you go to work, do you stay on weekends etc and based on this they program themselves to set your schedule automatically. A smart thermostat may take anywhere from 10 to 15 days (after installation) to learn the patterns and perfect the schedule. They continue to learn lifelong that they change themselves when your living habits change.

The key highlight of a smart thermostat is its high energy savings. Smart thermostats can save up to 23% of annual energy usage compared to an ordinary thermostat in place. In addition, smart thermostats can be controlled via WiFi, smartphone apps, most of them support voice control, they give energy usage reports and so on. Lets see some of the best smart programmable thermostat models.

#1 Nest 3rd Gen and Nest E – Smart Programmable Thermostats

The #1 choice we’ve in smart thermostat is Nest 3rd Gen and Nest E models. Nest 3rd Gen is the full featured smart thermostat model with all features & capabilities of a smart thermostat. Nest E is the budget model – which is basically a trimmed down version of the Nest 3rd Gen thermostat. You can read the comparison and see the difference between Nest 3rd Gen and Nest E in our review.

The prime difference between Nest 3rd Gen and Nest E is in features, compatibility and build quality. Nest E is compatible only upto 2 stage heating/cooling, whereas Nest 3rd Gen model is compatible upto 3 stage heating/cooling systems. Build quality is high for Nest 3rd Gen model and is available on steel or copper builds (Nest E is available only on plastic build). Some key features like Geo fencing is not avilable on Nest E. You can read our full review of Nest 3rd vs Nest E to see the comparison.

#2 Ecobee 4 and Ecobee 3 Lite – Smart Thermostats

Ecobee currently has two smart thermostat models available in the market – Ecobee 4 and Ecobee 3 Lite.  Out of these two models, Ecobee 4 is the full featured model with lots of features like self learning, built in Amazon Alexa, remote room sensor, and a lot of useful features. Ecobee 3 Lite is the budget model smart thermostat (a trimmed version of Ecobee 4 in features) which has all essential features needed for a smart thermostat but not as good as Ecobee 4.

The key difference between Ecobee 4 & Ecobee 3 Lite is that – the budget model Ecobee 3 Lite has no builtin Amazon Alexa & no remote room sensors are provided with. Also Ecobee 3 Lite is not compatible with HVAC accessories like dehumidifiers and ventilators. You can read our review of Ecobee 4 vs Ecobee 3 Lite to see the differences.

#3 Emerson Sensi – Smart Thermostat

Sensi is a popular WiFi thermostat from the automation giant Emerson. Sensi has all features of a smart thermostat (including geofencing) except the “self learning” feature. We’ve covered full review of Emerson Sensi in our guide.

In this article, we write about underfloor heating thermostats or radiant heat thermostats. Before diving into thermostat models, lets dig a little more about underfloor heating. “Underfloor heating” or “floor heating” is often referred to as “radiant heating” commonly in USA. Underfloor heating is applied to heat the floors to optimum temperature during the winter season. Even though most homes in USA employs central furnace based heating or heat pumps, the heat from these HVAC systems do not heat the floors properly. HVAC systems (like furnace or heat pumps) are designed to heat air and circulate hot air through out the interiors. They can keep your rooms & interiors warm but they fail to heat the floors to the desired temperature. You’ll feel a cold feet in such situations!

The solution here is “underfloor heating” – where a heating system is installed under the floor to maintain proper temperature during winters. Two types of systems are available for setting up “underfloor heating” – Electric based or Water based (known as Hydronic radiant heating). Read more about types of underfloor heating below this article.

Underfloor Heating Thermostats

As you know now, underfloor heating is setup as a separate system independent of the common HVAC system in your home. The thermostats you use for HVAC systems (like central furnace or heat pumps) may not be suitable for regulating your underfloor heating system. However, there are models that are compatible with both HVAC and underfloor heating systems. Nest thermostat is a classic example which can be used for regulating underfloor heating systems (suitable only for hydronic radiant systems). Companies like Honeywell has thermostat models dedicated for underfloor heating systems. Let’s see some of the best underfloor heating thermostats and how they differ!

Electric & Hydronic Thermostats – As we wrote above, there are two types of floor heating systems – electric & hydronic. A thermostat designed for electric floor heating system is not suitable for water/hydronic radiant heat system (and vice versa). So we’ve to list these thermostats separately to avoid confusion.

Electric Floor Heating Thermostats

Let’s first see some of the best electric floor heating thermostat models. An electric floor heating system uses electricity to heat the floors (a well insulated electric nest is installed underneath). They typically run on line voltage – 110 volts or 240 volts. So what you need here is basically a line voltage thermostat suitable for underfloor heating systems.

Programmable Thermostat for Underfloor Heating

Let’s first see the best programmable thermostats for electric underfloor heating systems. Programmable thermostats can be programmed to follow a preferred schedule (based on your lifestyle) and control your heating system accordingly. There are also WiFi enabled thermostat models for underfloor heating systems, which you can see below (#3 Nuheat WiFi thermostat) – which can be controlled via internet.

#1 – Honeywell TH115-AF-GA/U – Floor Heating Thermostat

This model from Honeywell (TH115-AF-GA/U) is one of the best selling underfloor heating thermostat. This model is 7 day programmable and it comes with a floor sensor (for better temperature control) and GFCI (ground fault protection) which is essential for line voltage systems. Three choices of heating mode are offered by this model: ambient or floor or ambient with floor modes – which can be set according to your system preferences.

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Technical Specifications to keep in mind:


radiant floor heating thermostat

Electric Underfloor Heating Thermostat

  • This thermostat is suitable for electric underfloor heating systems only.
  • Resistive load only – Make sure load type of your floor heating system is resistive.
  • Max current is 15A (in either case of 120 volts or 240 volts). If your heating system draws more than 15A, this thermostat is not compatible.
  • Max wattage is 1800 watts at 120 volts and 3600 watts at 240 volts. Check wattage requirements of your floor heating system and make sure its within the specified power rating.

#2 NuHeat Radiant Floor Heating Thermostat (Dual Voltage)

Our #2 choice is NuHeat radiant floor heating thermostat for electric underfloor heating systems. This model is  2 Day (week day/week end) programmable, comes with a 3.5 inch color touch screen display and is dual voltage (compatible with 120 volts or 240 volts). This model comes with “Energy Usage Monitor” – which helps to monitor your energy usage over a week or a month. You can reprogram your thermostat (based on the energy usage data) to save energy and save bills.

NuHeat - Check Price


  • Radiant Floor Heating Thermostat
    NuHeat – Underfloor Heating Thermostat

    Suitable for all types electric floor heating systems. Supports dual voltage (120 volts/240 volts)

  • GFCI – ground fault detection & cut off is builtin and is set at 5mA leakage.
  • Floor Type – suitable for tiles & stone based flooring. Temperature cut off limit set at 82°F for wooden floorings (laminate & engineered wood flooring)
  • Language support for English/French/Spanish
  • Customisations – like setting clock to 12h mode or 24h mode, screen brightness, °C or °F temperature display and a lot of other customisation options are available.
  • Auto/Manual mode – Choose an automatic schedule with auto mode and you can set a manual schedule with manual mode.
  • 3 operating modes – just like the Honeywell model above, this thermostat can regulate ambient air, floor temperature or both together in combined mode.

#3 WiFi/Wireless Radiant Underfloor Heating Thermostat by NuHeat

Our #3 choice is the WiFi variant of our #2 choice – NuHeat wireless radiant floor heating thermostat. This model has the additional WiFi feature along with all the features of the above listed #2 model. We placed this in #3 as WiFi models are a little costly and everyone doesn’t prefer an advanced WiFi termostat to manage floor heating thermostat.

All features & options are exactly the same as NuHeat Radiant Thermostat (#2 model). WiFi is the only add on feature for this model.

#4 SunTouch TouchScreen Underfloor Heating Thermostat

Our #4 choice is a touchscreen electric underfloor heating thermostat from SunTouch. This is a 7 day programmable thermostat with all essential features packed at an affordable budget. This model comes with a floor sensor for better regulation of temperature & heating system.


  • 3.5 inch touchscreen with bright display, 7 day programmable and Energy usage monitoring.
  • Compatible with electric underfloor heating systems upto 15A current rating.
  • Dual voltage compatible (120V/240V) and GFCI protection enabled.
  • Floor sensing & Air sensing modes available.
  • Floor sensor – 15 feet 10K sensor wire included with the model.
  • Upto 3 underfloor heating electric mats can be connected in a single thermostat (

Hydronic Floor Heating Thermostats

Hydronic floor heating thermostats are used to regulate hydronic underfloor heating systems – which are basically water based heating systems. Hydronic heating systems are usually two types : 1)Buried systems – where 1.6cm pipes are buried deep under the floor; 2) Surface mounted systems – where 1.2cm pipes are laid just on top of the existing floor. Hydronic thermostats are suitable for both types of hydronic heating systems irrespective of buried or surface mount. Let’s see some of the best hydronic thermostats available.

#1 Aube by Honeywell – TH140-28-01-B/U – Programmable Hydronic Thermostat

This model from Aube (by Honeywell) is our #1 choice in hydronic thermostats. Aube TH140-28-01-B/U is a 7 day programmable multipurpose thermostat suited for hydronic underfloor heating systems, millivolt gas fireplace heaters, boiler hydronic systems, radiant heating systems and line voltage heating systems.

Let’s see Highlights:

  • Compatible with a wide range of systems – 120 volts, 240 volts, millivolts, and 24 volts (low voltage).
  • Suitable for hydronic floor heating, gas fireplaces, line voltages systems (like baseboard heating). boiler hydronic systems and much more.
  • Current rating – 5A (resistive)
  • Pump protection to prevent pump seizure (activates pump for 1 minute in every 24 hours)
  • Low battery warning for 60 days

#2 Nest Smart Thermostat for in floor radiant systems

If you’re looking to install a smart thermostat for your underfloor heating system, Nest is the best option. If you already own a Nest thermostat in your home, you can use the same model to control your hydronic radiant heating system. Nest thermostat is equipped with “true radiant” feature which is specially built in for underfloor radiant heating systems or radiator heating systems.

Nest is a good choice (especially with true radiant feature), if you’re looking for a smart thermostat to regulate your whole home heating system (which includes an in-floor radiant heating system as well).  You don’t need to buy a separate thermostat for your underfloor heating system if you are opting Nest (which you can use for your conventional central heating system as well).

#3 Aube by Honeywell TH135-01-B/U – Non Programmable Hydronic Heating Thermostat

Our #3 choice is a non-programmable hydronic heating thermostat from Aube by Honeywell. If you prefer a low priced model (without programming option), this model is the best choice you can get with all essential features.This model is basically very similar to our #1 model in hydronic thermostats (Aube TH140-28-01-B/U) with no programming option.

Let’s see the highlights:

  • Compatible with hydronic floor heating systems, central heating systems, millivolt systems, & electric heat appliances using a relay.
  • Current rating: 2 Amperes (inductive load)
  • Low voltage thermostat – 24 Volts R,W
  • Remote input feature – change of temperature via telephone (if you’ve a telephone controller)
  • Low battery indicator – for upto 60 days.
  • Pump protection to prevent pump seizure (activates pump for 1 minute in every 24 hours)

The Learning Thermostat – Nest!

The Nest Smart Thermostats are manufactured by Nest Labs – an innovative company owned by Google currently. If you like stories, Nest Labs was started in 2010 by two Apple employees, Tony Fadell and Matt Rogers. The idea for an innovative, internet connected thermostat first sparked on Tony Fadell; when he was building a vacation home and found all the available thermostats inadequate. Driven by the idea, Fadell roped in Rogers to start Nest Labs in their garage. The first product Nest Learning Thermostat (1st Gen) was released in 2011 – and the product took off in no time. People really loved the new Nest smart thermostat – which was self learning, automatic and can be controlled via internet.

Nest released  2nd Gen thermostats with much improved design and features on October 2012. The company had grew from 0 to nearly 250 employees by this period. On January 14, Google acquired Nest Labs for USD 3.2 Billions in cash deal. So that’s the story about Nest in a nutshell – the first smart thermostat manufacturer.

Nest 3rd Gen and Nest E

Nest currently has two thermostat models – Nest 3rd Generation and Nest E. Both of them are smart thermostats, where Nest 3rd Gen is the full featured model and Nest E is basically a budget model (a trimmed down version of Nest 3rd Gen).

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The key difference between Nest 3rd Gen and Nest E thermostats is in compatibility, build quality and some features like display and color choices. You may read the complete comparison of Nest 3rd Gen vs Nest E give below.

Nest Thermostat Review
Nest E and Nest 3rd Generation Thermostat

Nest E and Nest 3rd Generation smart thermostats have many key features in common. They both are “self learning” – which means they program themselves automatically after installation. Nest E and Nest 3rd Gen – both are designed to give high energy savings, and they can pay for themselves within 2 or 3 years of installation (this will vary with your energy usage). WiFi connectivity is enabled for both models and they can be controlled from anywhere via Internet. They learn your living habits & patterns to re adjust the schedules themselves. Extra room sensors (temperatures sensors) can be interfaced with both Nest 3rd Gen and Nest E models – to manage any hot/cold spots in different rooms in your home.Voice control and Smart home integrations ( Apple Homekit, Google Home, Amazon Alexa) is enabled in both models of Nest thermostat.

In a nutshell, Nest 3rd Gen is compatible with different types of HVAC systems (covers nearly 95% of HVAC systems in USA), even with multi stage systems having 3 or 4 stages. Nest E is compatible with only 85% of HVAC systems, and when it comes to multi stage – Nest E covers upto 2 stages of heating/cooling only. Read our complete Nest thermostat compatibility guide to get more info. 

Nest 3rd Generation – Review

As you know, “Nest 3rd Generation” – is the full featured smart thermostat model from Nest. Apart from the key features mentioned above (common for Nest 3rd Gen and Nest E), what makes Nest 3rd Gen unique is its compatibility with more number of HVAC systems. Nest 3rd Gen also comes in different ring colors (choose from Copper, Stainless Steel, Black, and White colors) – where you can choose a color that best fits your interiors. Nest 3rd Gen also has unique features like “FarSight” – which lights up the display (to show temperature, time and weather) when someone is spotted in the room.  Let’s go deep into features of Nest 3rd Gen thermostat.

Features of Nest 3rd Gen Thermostat

As I said, Nest 3rd Gen is a true smart thermostat with a load of useful features. Many of these “smart features” are common to Nest 3rd Gen and Nest E. Let’s see all of them in detail.

Self Learning – is the highlight feature of both Nest thermostat models – Nest 3rd Gen and Nest E. You don’t need to program your thermostat by manually inputting temperature schedules. Instead, just install your Nest 3rd Gen or Nest E and leave it alone. The Nest thermostat will start building patterns based on your lifestyle/living habits and programs itself.

The “self learning” feature is built on top of sophisticated artificial intelligence software, that it understands when you’re sleeping (adjusts the temperature for a good nights sleep), when you wake up (adjusts temperature for a warm morning), when you go away to office (moves itself to eco mode to give you max energy savings) and more.

Note: If you prefer a custom schedule over the “self learning” feature, you can program Nest thermostats using the Nest App – the mobile app for android/iOS devices.

Energy Savings  – is the next key feature of Nest smart thermostats. Both models (Nest E and Nest 3rd Gen) are built to provide high energy savings by controlling your HVAC system to operate at maximum efficiency. As claimed by Nest, both thermostats are capable of giving an energy savings of 12% on heating bills and 15% on cooling bills. These numbers would vary with regions, types of HVAC and a lot other factors. I believe, anyone can expect a savings rate in the range of 8% to 15% on annual energy bills.

Paying for itself – if you look at a white paper in Nest, they claim a Nest thermostat can pay for itself in 2 years time frame. Nest claims an average savings in the range of $100 to $150 annually.

Nest E and Nest 3rd Gen are both “ENERGY STAR CERTIFIED” thermostat models. “ENERGY STAR” is a certification provided in USA (backed by government) for products that save energy and protect environment.

Voice Control & Smart Hubs – Nest 3rd Gen and Nest E can be controlled using your voice. To enable voice control, you need to interface your thermostat to a smart home hub like Apple HomeKit. Both Nest thermostats are compatible with all popular smart hubs like Apple HomeKit, Google Home, Amazon Alexa, Samsung SmartThings, IFTTT and more.You can change temperature settings, turn ON/OFF, and do many other things using voice control. The key benefit here is, you don’t need to depend on your mobile app to adjust temperature or do some action on your thermostat.

WiFi Connectivity & The Nest App – Does it sound cool to control your home thermostat sitting in your office chair ? Both Nest models are equipped with WiFi connectivity and can be controlled over internet using the Nest mobile App.

Energy Reports – helps to analyse your home energy usage. “Daily energy usage” is monitored and displayed on the Nest App. Reports are created every month showing analysis & patterns of energy usage.Based on the report, you can adjust your living habits or schedules to save more energy in coming months. Energy reports are available for both Nest E and Nest 3rd Gen models alike.

Extra Room Sensors – you can interface extra room sensors (you’ve to buy separate) with both Nest 3rd Gen and Nest E thermostats. You can install separate room sensors in individual rooms, say your kids room or master bedroom or wherever you prefer. This way you can manage any hot/cold spots in your home. A zoned hvac management system can be built using a single Nest thermostat and a couple of extra room sensors.

Unique Features of Nest 3rd Gen Model

All of the features discussed above are common to both Nest 3rd Gen and Nest E models. Now let’s see what makes Nest 3rd Gen model unique and premium.

FarSight – is a feature unique to Nest 3rd Gen model. “FarSight” activates the sleeping display whenever someone’s presence is detected on the installed room. Nest detects any human presence within 20 feet radius of the installed location.

Bigger Display – Nest 3rd Gen has a bigger display with high resolution. The screen is 40% larger compared to Nest 2nd Gen model and the display is clear, bright and sharp.

Ring Colors – Nest 3rd Gen gives you 4 choices in ring colors – Copper, Stainless Steel, White and Black colors. You can choose one that best suits your home interiors.

Higher Compatibility – Nest 3rd Gen is compatible with almost 95% of HVAC system types used in USA. Nest thermostats goes well with central furnace systems, boiler based systems, Heat pumps with or without auxiliary heating, and systems with central air conditioning – which are the most common used HVAC system types in USA.

Note: Nest thermostats (both Nest 3rd Gen and Nest E) are not compatible with line voltage systems like baseboard heater, convection heaters and forced fan heaters.

Secure Boot Technology: Ensures that the Nest software is running alone, by blocking all unwanted or  malicious software. It  also safeguards your data and hence protects your privacy.

Remote Control: Controlling the thermostat from anywhere is possible using your mobile phone, laptop or tablet using application making it very user friendly.

Alerts: Gives alert when something goes wrong.


Energy Efficiency: The Green leaf function helps you to identify when the thermostat is working in the energy efficient mode.

Geo-fencing: Sets temperature by learning your location with the help of your Smartphone.

To prevent overheating, they have “Heads-up” feature that will turn off the device to prevent overheating. This feature also helps to save energy.

Installation is pretty easy as it takes hardly 30 minutes for the entire procedure.


  • The  green leaf icon lights up when the thermostat is in energy saving mode. This feature helps us to reduce energy consumption.
  • Takes minimal time for installation.
  • Bigger display with greater resolution giving sharp and clear reading.
  • Enhanced learning capability.


  • Nest Gen 3 has no remote sensors, hence the thermostat monitors only the temperature near it.


This version of Nest offers some great features as like updation from near field technology to far field technology. The improved resolution and bigger display gives more clarity to the readings. It is considered to be the easiest model to install and works with many Smart Home Partners. It supports water boilers and comes in different colour options. Works with Alexa for voice control. It is great choice for every home giving a very attractive appearance.

Nest E Review

It is the latest model of Nest thermostat, launched in 2017. It comes with a new simplified design with almost all features and is cheaper in price. They look much plainer rather than having a big metal Ring with a bright screen. Nest E thermostat looks duller with Plain White puck and they really can’t be noticed easily. All you need to do is setting the thermostat in the initial few weeks and then the rest will be taken care by its own built-in intelligence. Frosted glass tops the display making the display look dimmer. It has a simpler interface. Like all other Nest thermostats, E version can be connected to internet and can be controlled using mobile application. Using your phone and other sensors, Nest E can easily identify whether you are at home or not and thereby sets temperature accordingly. It helps to save about 12% on heating and 15% on cooling bills each year. The only difference from other thermostats is that it doesn’t have ‘farsight’ feature which enables you to know the time and temperature by turning the display on automatically when you are around. E version is compatible with almost 85% of heating or cooling devices at your home. Like all other thermostats, E has sensors to detect motion, humidity, proximity and temperature and can also integrate with third party services like Amazon’s Alexa and Google’s Assistant or Apple’s HomeKit . Few of its main features are:

  • Remote Control:  You can control the thermostats from anywhere using your mobile phone, laptop or tablet using application making it very user friendly.
  • Energy History: They help you to know how much you save on your energy bills and also provide awareness on how to save more.
  • Fault Alerts:  Nest can indicate if any of your HVAC systems that are connected to the thermostat goes faulty. Hence you can identify and rectify the faulty system.
  • Nest Leaf: The display lights up when the temperature setting you have chosen is an energy efficient one. This feature clearly helps you to identify if you are on the right setting.
  • Scheduling: Set the thermostat in the initial few weeks of purchase as per your requirement, later on the thermostat itself will learn your schedule and sets the temperature accordingly but providing you with the choice of changing it anytime from anywhere.
  • Sensors: The sensors added to it help you to identify temperatures of different rooms and enables you to set priority accordingly.
  • Away Mode: With the help of motion sensors and by studying your current location with the help of your mobile phone, the thermostat can turn itself off after ensuring you are away.
  • Easy Installation: Its simple structure made the installation part easier and it hardly takes around 30 minutes to install Nest E.
  • Attractive Design: The display is topped with glass giving it a frosted look and thereby it blends beautifully to where it is affixed. One can hardly notice it especially when it is off.
  • Alexa Enabled: You can just talk to your Echo or Dot regarding temperature settings and the thermostat responds accordingly.


  • They can study your routine
  • Very attractive model
  • Compatible with most of the HVAC devices
  • It can be programmed to set desired temperature
  • Simple installation
  • Simplified design where you can twist the dial to adjust the temperature
  • Reduced price but  offers all important features
  • They have pre-cooling or pre-heating features


  • Have the need to have a C wire
  • Fails to support certain HVAC systems
  • Absence of farfield technology
  • Blurred display can cause inconvenience for people with vision problems


The strength of Nest E is mainly its simplicity to use and its simple design at a reduced price. The Nest Thermostat E box contains the thermostat, back plate with wire terminals, two mounting screws, optional mounting plate and a detailed installation guide book. Its display hides all unnecessary readings making the display look neat and jus displaying the temperature in a bigger size. Except for its inability to support some of the HVAC systems, it is great for your home offering you get all the important features at a reduced price.

Nest E Vs Nest 3rd Gen

Nest E and Nest Generation 3 both look almost the same with almost similar features. Your choice can mainly depend on the budget or the appearance. Both have similar learning routine and uses Nest App. There are only slight variations which will be discussed below.

    • Price: E is much cheaper as it is made of plastic and not metal like the other versions. Hence it is definitely a budget model.
    • Design and Appearance: E has an inferior display. It has a frosted glass over the dial giving a dimmer reading. Whereas Nest 3 has a bigger screen with greater resolution giving a sharper and clear reading. The frosted display of E blends the thermostat beautifully with the wall giving it a very classy look. Nest 3 comes in 3 different colours unlike E which is white.
    • Farsight : Nest 3 has this feature which wakes up the display when it senses your presence near the thermostat and shows you the information you prefers to see. E lacks this feature even if it has this same motion sensing sensors. This  cannot be considered as a major drawback.
  • Compatibility with HVAC systems: Nest 3 is compatible with more HVAC units when compared with E. Say if Nest 3 goes well with 95% HVAC units, then for E it will be around 85%. Nest compatibility tool helps you to check compatibility with your devices.
  • Pre-set scheduling: This feature comes with E which helps you to save money instantly. You can also reprogram it using Nest App or using Smart Home Assistance.
  • Sensors: Nest 3 comes with few more sensors than E.

Below table shows a quick overview of the similarities and difference among the two


Category Nest Gen 3 Nest E
Size 3.25 in diameter

1.21 in thickness

3.19 in diameter

1.14 in thickness

Display Superior Display

3.25 in diameter

480 x 480 px resolution

Inferior Display

1.76 in diameter

320 x 320 px resolution

Sensors Temperature(10 nos)


Near-field activity

Far-field activity

Ambient light



Proximity/ Occupancy

Ambient light

Connectivity 802.11b/g/n @2.4GHz
802.11a/n @5GHz
802.15.4 @2.4GHz
Bluetooth LE
802.11b/g/n @2.4GHz
802.11a/n @5GHz
802.15.4 @2.4GHz
Bluetooth LE
Features Auto-Scheduling
Nest Leaf
Energy History
Time to Temperature
System Match
Early On
Heat Pump Balance
Water / Boiler control
Nest Leaf
Energy History
Time to Temperature
System Match
Early On
Heat Pump Balance
Water / Boiler control
Price More Less
Material used for making Metal Polycarbonate
Appearance Easily noticeable Blends really well with the walls
Far-sight feature Yes No
Compatibility with HVAC systems Compatible with 95% of HVAC Systems Compatible with only 85% of HVAC Systems



To wind up, it is very much clear that both versions of Nest aren’t much different except for very few features. So either Nest E or Nest gen 3 is going to make your home smarter, ensuring a comfortable atmosphere all around.

Ecobee currently has two smart thermostat models available in the market – Ecobee 4 and Ecobee 3 Lite.  Out of these two models, Ecobee 4 is the full-featured model with lots of features like , built in Amazon Alexa, and a lot of useful features. Ecobee 3 Lite is the budget model smart thermostat (a trimmed version of Ecobee 4 in features) which has all essential features needed for a smart thermostat but not as good as Ecobee 4.In this guide, we review Ecobee smart thermostats and compare Ecobee3 Lite vs Ecobee4 – two best selling thermostat models from Ecobee. 

Ecobee3 Lite and Ecobee4 integrate well with Amazon AlexaApple HomeKitGoogle AssistantSamsung SmartThings,  Microsoft’s Cortana, and other home automation hubsEcobee thermostats can be controlled using the touchscreen (available on thermostat) or your smart phones/tablets from anywhere in the world. They also help to set reminders for HVAC maintenance, UV lamp or furnace filter replacement, alerts for low/ high temperature or humidity. They offer you a feeling of comfort in no time.

Ecobee 4 and Ecobee 3 Lite


The prime difference is Ecobee 4 has built in Amazon Alexa & comes with a room sensor (1 room sensor included); where as Ecobee 3 Lite has no built in Amazon Alexa & no room sensor provided with the product (you’ve to buy room sensors  & Alexa device separately).  See our comparison Ecobee3 Lite vs Ecobee4 for more differences!

Ecobee3 Lite & Ecobee4 – Compatibility Guide

Before buying an Ecobee Thermostat, you’ve to first check if  the model in your mind (Ecobee 4 or Ecobee 3 Lite) is compatible with the current heating/cooling system in your home. We are listing out a few important points to check & verify.

#1 – Line Voltage or Low Voltage  – identify if your heating/cooling system is line voltage or low voltage. Ecobee thermostats (both models) are designed for low voltage systems only. They work well with 24V HVAC systems like central furnace, boilers, heat pumps etc.  You should not buy an Ecobee model, if you’ve line voltage systems like Baseboard heaters, forced fan heaters as your heating source.

#2 – Stages of Heating/Cooling systems – Conventional HAVC systems (like a central furnace) are either single stage or multi stage. Ecobee thermostats (Ecobee 4 & Ecobee 3 Lite) support both single stage and multi stage systems. In the case of a multi stage HVAC system, they support 2H/2C – which means 2 stages of heating & 2 stages of cooling.

#3 – Heat pumps – Ecobee thermostats support all heat pump models including heat pumps with auxiliary/emergency heating. Ecobee 4 supports heat pumps (4H/2C – 4 heating stages & 2 cooling stages) and for heat pumps with aux heating (2H – 2 stages auxiliary heating). Take note Ecobee 3 Lite supports only 2H/2C (2 stages of heating & cooling, marked as Y1 and Y2) of heat pumps and 2H (2 aux heating stages, marked W1 and W2) of Heat pumps with aux/emergency heating.

Note: In case of auxiliary heating, both Ecobee models support gas, oil, electric or dual fuel sources.

#4 – Boilers – Both models support 2H/2C (2 stages of heating W1 and W2) in the case of boilers. For cooling, they support 2 stages of forced air cooling (known as 2 transformer configuration).

#5 – Accessories – Ecobee 4 supports all types of accessories like humidifiers, dehumidifiers, ventilators (ERV & HRV). Ecobee 4 comes with terminals for connecting accessories. Pleas note Ecobee 3 Lite does not support any accessories and there are no terminals provided on Ecobee 3 Lite to support accessories.

#Final – Use the compatibility checker tool provided in Ecobee website and see if your system is compatible.

Ecobee4  Smart Thermostat Review

Ecobee4 – is the fourth generation smart thermostat from Ecobee, with built in voice control feature. The Amazon’s Alexa is built into Ecobee4 – which means just talking to the device from anywhere inside your home (the microphone has high sensitivity that Ecobee4 will capture your voice even across the room) is all you need to do to control – like setting the timer, or turning it OFF or whatever! .

Energy Savings! The Highlight

The highlight feature of an Ecobee thermostat is energy savings! Ecobee claims to save on average 23%  of energy utilization every year.Obviously the company might have tested this on ideal conditions (without extreme temperature variations) but I think its great if you get anywhere near 20% and that’s considerable savings of money. You can get the money invested in an Ecobee thermostat back in just 2 or 3 years with this kind of energy savings.

Check Price & View Details

Real Time Control via Mobile Apps

Ecobee4 works on real time when connected to the internet. Both models (Ecobee 4 and Ecobee 3 Lite) comes with a mobile app which you can install in your smartphones to control the device from anywhere (anywhere in the world provided your thermostat is connected to internet).

Room Sensors

 Ecobee4 comes with an extra room sensor (only 1 sensor provided) which  helps you to manage hot/cold spots. You can install this room sensor in a favorite room of yours (possible your master bed room) and this sensor will help to eliminate any hot/cold spots in this room. Usually thermostats (which has built in sensors) are installed in the common living room and it wont sense temperature/humidity level in other rooms leading to uneven temperature in some areas. This extra sensor solves this pain point. 

Additional Sensors: If you need extra sensors, you can purchase a couple from Ecobee separately and pair them with your thermostat.

In addition, the company provides excellent customer support and a long three-year warranty. The following are its main features:

# Built in Alexa: – This makes Ecobee4 more than a simple smart thermostat. All you need to do is just talk to your new friend, Ecobee4. Accordingly it sets the temperature, timers, alerts and reminders.  The best thing here is you can avail all features of Alexa along with the thermostat, like you can integrate it with almost all your home appliances and control them. The integrated alexa can also read news, make changes in temperature, turn on/off the lights, play music, book uber etc.

# Design: – Ecobee4 has a beautiful design with a classic touchscreen that displays the mode, humidity level of indoors, current temperature settings and various updates and alerts. There is a blue LED line at the top which indicates when Alexa responds to your queries. The product dimension is 1x4x4 inches.

# Ease of installation: –   While most other smart thermostat models take up to 40 minutes to install, the Ecobee4 takes less than 15 minutes as it comes with a built in leveler making it ready to install.

# No Need of C-wire – If your home doesn’t have a C wire, installation can take a little longer because you need to install the included Power Extender Kit. It works with nearly every kind of HVAC system (except baseboard heaters/line voltage systems) and there is a detailed walkthrough in the manual that comes along with it. Read the compatibility guide we have presented above.

Note: If you don’t know which is your current thermostat or which is your present heating/cooling system, read our guide to – Identify your heating/cooling system.

# Far field technology: – This feature enables you to talk to the thermostat from anywhere across the room. As I wrote before, Ecobee 4 has a powerful microphone which fetches voice commands from far away places (than where the thermostat is installed.

# Sensing and operating: – These smart thermostats save energy by learning your habits and thereby adjusting to maximize your comfort (and max energy savings).

# Geofencing: – This feature tracks the location of the owner and the thermostat automatically acts to make the temperature at the most comfortable level when owner arrives home.

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                                  Ecobee4 is truly a smart thermostat with Alexa built in making the interaction as interesting as talking to your friend. A true friend to your smart home, with the ability to control everything from its voice activated assistance. If you wish to own a fully featured, truly smart thermostat – go for Ecobee 4 without second thoughts! You’ll be rewarded in the long run!

On the other side, if you don’t have that high budget and still wish to own a smart thermostat – go for Ecobee 3 Lite. Read the full review given below.

Ecobee3 Lite Review

As I already wrote before, Ecobee 3 Lite is a budget model smart thermostat from Ecobee. This model is basically a trimmed down version (in features) of Ecobee 4. The prime difference is Amazon Alexa and enclosed room sensors – where Ecobee 3 Lite doesn’t have a built in Alexa feature and no room sensor is enclosed with the package. You’ve to buy both separately! The good side is compatibility – Ecobee 3 Lite is compatible with Amazon Alexa & extra room sensors can be interfaced if you really want them later.


Highlight Features:

  • Self Learning – Just like Ecobee 4 , this model is ‘self learning‘ and programs itself after analyzing your living habits and patterns.
  • Budget Model (lower price) – when compared with Ecobee 4 -the full featured model.
  • Monthly Energy Reports can be obtained to study about the device’s performance and even gives you tips to improve savings.
  • Smart Hub Integrations – with IFTTT, Amazon Alexa,  Echo, Echo Dot, Apple HomeKit, Wink and SmartThings.
  • Smart Recovery – feature can track your local weather throughout the day with the help of internet and heats/cools your home accordingly.
  • Easy to use and has a very fast responsive touchscreen.
  • Vacation mode can be activated when you are away from home for an extended period of time.
  • Alerts and reminders help you by notifying at the correct time when something goes wrong.
  • Effortless control at your finger tip as you can adjust the temperature and comfort settings from anywhere around the world using your android and iOS devices including apple watches.
  • Room Sensor Compatibility – comaptible with wireless Ecobee room sensors. You can interface upto 32 room sensors with an Ecobee thermostat (be it the Ecobee 4 or the Ecobee 3 Lite model)
  • Sleek Design –  The display size is 3.5 inches. The product dimension is 4.05×4.05×0.84 inches


  • Lacks Geofencing – which is a feature that detects if you’re away or nearing home from work. When you are near your home, this feature will turn the heating system ON and preheats your home to a comfortable level before you reach home. 
  • Lacks accessory terminals – required to control HVAC accessories such as humidifiers, dehumidifiers and ventilators.

Ecobee3 Lite vs Ecobee4  – Comparison

The prime difference between Ecobee3 Lite vs Ecobee4 – is that Ecobee3 Lite is a budget model smart thermostat, whereas Ecobee4 is a full featured smart thermostat.  Ecobee4 comes with builtin Amazon Alexa and an extra room sensor, but you’ve to purchase them separately (if you really need) for Ecobee3 Lite. Another noticeable difference is the proximity sensor and geo-fencing feature present in Ecobee4 but lacking in Ecobee3 Lite. 

Well, these are some important differences between Ecobee3 Lite and Ecobee4. Let’s see a detailed comparison between Ecobee3 Lite and Ecobee4 below.

Note: #HVAC Accessories – Another important difference to note is about “hvac accessories”. Ecobee4 supports hvac accessories like humdifiers, dehumidifiers, and ventilators (ERV, HRV). Ecobee3 Lite does not support any kind of hvac accessories.

Ecobee4 vs Ecobee3 Lite
Ecobee4 vs Ecobee3 Lite

# Design  – If you just glance, both Ecobee3 Lite and Ecobee4 would look same to your eyes. But Ecobee4 has a glowing LED bar on top, which shines when Alexa is activated. The dimensions are almost same for both, but Ecobee3 lite is smaller in size (4 inch length, 4 inch width and 0.8 inch thickness) and Ecobee4 is bigger comparatively (4.29 inch length, 4.29 inch width and 1 inch thickness).

# User Interface – Ecobee4 and Ecobee3 Lite comes with a 3.5 inch touch screen (full color), built on 320×480 resolution. Both models display current temperature, humidity, status (off, heat, cool), alerts, and features for various manual adjustments. Ecobee4 has a button to activate Alexa manually. The web/mobile app interfaces are same for both models. 

# Integrations – All Ecobee models are third party integration friendly. Ecobee4 has built in Alexa making it smartest of all thermostats. You need to buy Amazon Echo or Echo Dot separately to pair it with Ecobee3 or Lite versions. Ecobee4 eliminates the need for this separate purchase as it has Alexa built into it. Except for this all Ecobeessynchronise perfectly with IFTTT, wink, smartThings and Apple HomeKit.

# Operating patterns and sensing – They save upto 23% of energy by learning habits and routines and there by maximizing your comfort. Ecobee4 have room sensors to attain better control.

Unlike Ecobee4, Ecobee3 doesnot support geofencing which helps to automatically track you and make your home comfortable when you reach near. Ecobee4’s mobile app has geofencing feature. All Ecobee thermostats can check and change temperature of your HVAC using mobile application or through web.

    From the above observations it is clear that Ecobee4 version is the smartest. So if you have enough budget, then go for it without  second thought. The smarter ones for a smarter home.

Ecobee Thermostat – C Wire Requirement

Most of the smart/WiFi thermostat models (like Nest, or Sensi ST75 or Honeywell RTH9585) require a C wire or common wire in your home electrical circuit. Ecobee thermostats also works well with a C-wire connection. But if you don’t have a C-wire or common wire in your home electrical circuit, dont worry! Ecobee has a workaround for homes that don’t have a C wire.

Ecobee 3 Lite and Ecobee 4 - Power Extender Kit
Power Extender Kit – Ecobee

Ecobee thermostats (Ecobee3 Lite and Ecobee4) ships with a PEK (Power Extender Kit) – which is for homes without a C wire. You’ll need to connect the PEK to the control board of your HVAC system (a furnace or heat pump only). Once the PEK is connected properly, you’ll need to wire the Ecobee thermostat according to the instructions given for installation with a PEK. You may check the installation steps of Ecobee to get a detailed idea.

The take away here is, you can buy an Ecobee thermostat without worrying about the C wire/common wire in your home. Both Ecobee thermostat models (Ecobee3 Lite and Ecobee4) can be installed irrespective of your home having a C wire or not.

Lets Wind up!

Ecobee thermostats are undoubtedly the best in smart thermostat category, and they stand at par with Nest by all standards. If we compare Ecobee 4 vs Nest 3rd Generation, I would give some extra points to Ecobee 4 as it ships with a remote room sensor (and an option to add more remote sensors as required). Remote room sensors helps to manage uneven heating (hot/cold spots) in some zones or areas. If you don’t prefer remote sensors, then Ecobee 4 & Nest 3rd Gen stand equal in many important parameters.

However, recall that Nest has “self learning” feature and it programs itself; whereas Ecobee thermostats are not “self learning” and you’ll have to program the thermostat or use a preset schedule. Ecobee claims 23% annual energy savings on heating bills, whereas Nest claims 13 to 15% annual energy savings on heating bills. These savings rates are manufacturer claims and may not reflect actual savings when you install them.

Note: At the time of publishing this review, extra temperature sensors (room sensors) were not available for Nest thermostats. But recently Nest has introduced additional room temperature sensors to manage hot/cold spots. These room sensors can be interfaced with Nest 3rd Gen or Nest E model. However, you’ll have to purchase this sensor separately for both Nest thermostat models.

The budget models of Ecobee & Nest  – Ecobee 3 Lite and Nest E are also comparable by all standards. So when it comes to choosing Nest or Ecobee, its more of a personal choice than judging by features. However there are compatibility differences (for different HVAC systems), so you may ensure your choice is compatible with your system.

 We at ThermostatGuide, aims to help you choose the right thermostat. We’ve covered every detail about the two Ecobee smart thermostat models – Ecobee4 and Ecobee 3 Lite. We’ve also compared Ecobee3 Lite vs Ecobee4, taking almost every detail into account. We hope, you’d have made your mind now. 

If you’re a homeowner, you’ll definitely have a heating/cooling system installed in your home. Based on your location, home size & other factors – the type of heating/cooling system would vary. In this article let’s learn more about types of heating/cooling systems and how to identify the one you’ve in your home. Basically, we can classify heating/cooling systems into two types based on the stages of heating/cooling provided – they are 1) Single Stage and 2) Multi Stage – heating/cooling systems. Let’s see them in detail.

A heating/cooling system is technically known as an HVAC system (Heating, Ventilation, Air Conditioning). A single stage HVAC system has only one stage of heating or cooling output. They are either running at full capacity (ON state) or not running at all (OFF state).

A multi stage HVAC system has more than one stage of heating/cooling output. The most common multi stage system is Two stage heating/cooling system – which has two output levels of heating/cooling. A two stage HVAC system will have a low setting & high setting suited for moderate climate conditions & extreme climate conditions.

If the winter/summer is not on the extreme side, you just need to run your two stage HVAC on “low setting” which will adjust your room temperature gradually. If the climate is on extreme side, put your 2 stage HVAC on the “high setting” which will adjust your room temperature quickly.

Other than two stage systems (the most popular and common model), there are three stage & four stage systems – in multi stage heating/cooling systems. The cost of the system increases with the number of stages. In North America (USA & Canada), most of the homes runs on single stage or two stage heating/cooling systems. Single stage systems are the least priced & easy to install. But they’ve the disadvantage of lesser fuel efficiency & uneven heating (recall they are either running at full capacity or OFF). Two stage systems costs high to install (& setup) but they are highly efficient (fuel costs would be lesser) & they provide even temperature to all rooms.

Do you know which type of HVAC system are you having in your home? If not, don’t worry! We will help you identify your type of heating/cooling system.

How to identify your heating/cooling system ?

The very first step in identifying your hvac system correctly is to first check if you are having a line voltage (120V/240V) system or low voltage (24 volts) system in your home.  If you have a line voltage system, you probably have an electricity based heating or air conditioning system in your home. In such case, you would be having a baseboard heater or a forced fan heater or a wall heater in your home. Now if you have a low voltage system in your home, you would be having a furnace based system, or a boiler system or a heat pump (this could be single stage or multi stage).

Now how to identify if you have a line voltage system or low voltage system? This is very simple – just check your thermostat wiring. The easiest way is to check the backside wiring of your current thermostat. If you have a line voltage system, your thermostat (which would be a line voltage thermostat running on 120 volts/240 volts) would have either two or four wires coming out of its backside. These wires will be thick (just like your mains line wire) and the color of wires will be either Black & Red or Black & White.

If you have a low voltage system, your thermostat (which would be a low voltage thermostat running on 24 volts) would be having 2 to 9 wires (or more) on its backside – which will be very thin sized and the wires will be having different colors like Green, Yellow, Red, White etc. Read our complete guide on how to identify between Low Voltage & Line Voltage Systems.

Identify between – Single Stage/Multi Stage – for a 24 Volts/Low Voltage System

In America, only 10% of homes runs on line voltage system (electricity based systems). The big majority (about 90%) of homes in USA & Canada runs on central furnaces, boilers or heat pumps – which are low voltage systems (which don’t need electricity to produce heat) and these systems are controlled using low voltage thermostats. These type of HVAC systems would be using a central furnace (in most of the cases) or a central boiler or a heat pump. In some cases, a combination of furnace & heat pump is used to setup the HVAC system. In any case (be it a furnace or boiler or pump), your HVAC can be either single stage or multi stage depending upon the levels of output provided by your system. This means it is possible to setup single stage or multi stage system using furnace or boiler or whatever source of energy. Our objective here is to identify if your system is Single stage or Multi stage – we are not bothered about if you have a furnace or a boiler.

Let’s see how we can do it easily! For this case also, lets grab the thermostat and look at its backside. Take the base off your thermostats and look at the wires. Check the wires going into terminals W, W1, Y and Y1 in particular.

Identifying Single Stage Heating/Cooling Systems

Conventional Single stage systems – will have one wire leading into W or W1 terminal (for heating) and one wire leading into Y or Y1 terminal (for cooling). So that’s the easiest way to identify single stage conventional hvac systems (which would be furnace based or boiler based).

Thermostat for Single Stage Heating or Cooling System
Single Stage HVAC System Thermostat – Source

Single Stage Heat Pumps – will have only one wire (for both heating and cooling) leading into Y  terminal.

Note: If the heat pump has emergency heat/auxiliary heating facility, you will find a wire leading into AUX terminal.

identifying single stage heat pump
Wiring – Heat Pump Thermostat (Single Stage)

Identifying Multi Stage Heating/Cooling Systems

Multi stage HVAC systems will have multiple wires (both for heating & cooling) leading into different terminals. The wires for heating purpose will be leading into terminals marked “W” (like W, W1, W2) and the wires for cooling purpose will be leading to terminals marked “Y” (like Y, Y1, Y2)

  • 3 Stage conventional heating system – will have wires leading into W, W1 and W2 (or W1, W2 and W3) terminals of thermostat.
  • 2 Stage conventional heating system – will have wires leading into terminals W and W1 (or W1 and W2)
  • 2 Stage conventional cooling system – will have wires leading into terminal Y and Y1 (or Y1 and Y2)
Two Stage Thermostat – 2 heat/ 2 cool option

Note: This image given above is of a thermostat which supports 2 stage systems (2H/2C – 2 stages of heating(W1, W2) & cooling (Y1, Y2) in a single thermostat). But this thermostat is actually wired as 1H/1C system as there is a jumper wire connecting W1 to W2 and another jumper wire connecting Y1 to Y2. This could be because the HVAC was either single stage or they want to use only 1 stage (possibly the moderate setting) of the 2 stage HVAC system. If the HVAC was a two stage system, we would have seen two separate wires going into W1, W2 and another two wires (if the system has air conditioner)  going into Y1 and Y2 terminals.

3H/2C – Thermostat with 3 Heating and 2 cooling option

Note: This image above is a thermostat that supports 3H/2C. But it is wired for as 2H/2C (2 stages of heating & cooling). You can see the jumper wire connecting W3 to W2 – which wires the thermostats as 2H.

Some systems have emergency heating (or auxiliary heating)

Thermostat with Two Labels (Double Label)

In some cases, a thermostat will be having two labels at the terminals (as shown in image below). One set is for conventional systems (furnace or boiler) and the other set is used if you have a heat pump.

Double Label Thermostat
Two Label Thermostat – Credits

Note:  In the image above, even though the wires are coming out of label marked “conventional” – this thermostat is actually wired for “heat pump”. So be informed, in this type of cases you can’t judge your HVAC system just by looking  where the wires are coming out from. You need to have an idea of wiring diagrams in this kind of cases.