In this article, we write about underfloor heating thermostats or radiant heat thermostats or heated floor thermostats, which are thermostats designed to control floor heating systems. Before diving into different thermostat models, let’s dig a little more about underfloor heating and the systems used. “Underfloor heating” or “floor heating” is often referred to as “radiant heating” commonly in the USA, and floor heating systems are installed to heat the floors to optimum temperature during the winter season.
Even though most homes in the United States employ central furnace based heating or heat pumps, the energy from these HVAC systems does not heat the floors properly. HVAC systems (like furnace or heat pumps) are designed to heat air and circulate hot air throughout the interiors. They keep your room interiors warm but they fail to heat the floors to the desired temperature. You’ll feel 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). These floor heating systems are controlled using specially designed thermostats known as heated floor thermostats.
Underfloor Heating Thermostats
As you know, a floor heating system is set up separately independent of the common HVAC system in your home. The thermostats you use for HVAC systems (like a central furnace or heat pump) may not be suitable for regulating your underfloor heating system. However, there are some models that are compatible with both HVAC and underfloor heating systems. Nest thermostat is a classic example that can be used for regulating underfloor heating systems (suitable only for hydronic radiant systems). On the other hand, companies like Honeywell, Nuheat, and SunTouch have thermostat models dedicated to floor heating systems. Let’s see some of the best thermostats for radiant floor heating systems and how they differ with each other!
The 2 Types – 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 listed the 2 types 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 compatible with underfloor heating systems.
Programmable Thermostat for Underfloor Heating
Let’s first see the best programmable thermostats for electric floor 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 the internet.
#1 – Honeywell TH115-AF-GA/U – Floor Heating Thermostat
Honeywell (TH115-AF-GA/U) is one of the best selling electric floor heat thermostat. This model is 7 days 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, floor and ambient with floor modes – which can be set according to your system preferences.
A thermostat with floor sensor provides the benefit of keeping the floors constantly at the set temperature (not getting too cold/hot). If there is no floor sensor, there’s a rare chance of the floors getting overheated or becoming too cold, while the floor heating system attempts to attain the air temperature.
Technical Specifications to keep in mind:
- This thermostat is suitable for electric underfloor heating systems only.
- Resistive load only – Make sure the 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 it is within the specified power rating.
#2 NuHeat Radiant Floor Thermostat (Dual Voltage)
Our #2 choice is the NuHeat radiant floor heating thermostat for electric underfloor heating systems. This model is 2 Day (weekday/weekend) 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.
Though we’ve listed Nuheat Home as 2nd choice (owing to high price compared to Honeywell), this model is in fact one of the best heated floor thermostats available. Nuheat home model has two temperature sensors, a floor sensor, and an air temperature sensor. GFCI protection is enabled to prevent electrocution due to leakage of current underneath.
- Suitable for all types of 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 the 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 ‘auto’ mode to follow the programmed schedule and ‘manual’ mode to bypass the programmed schedule and set your own custom temperature.
- 3 temperature sensing modes – just like the Honeywell model above, this thermostat can regulate ambient air, floor temperature or both together in the combined mode.
#3 WiFi Radiant Floor Heating Thermostat by NuHeat
Our #3 choice is the WiFi variant of the above model – NuHeat Signature wireless/WiFi radiant floor heating thermostat. This model has an additional WiFi feature along with all the features of the above-listed #2 model. If you prefer a WiFi-enabled thermostat for your floor heating system, Nuheat Signature is the goto model.
Nuheat Signature is compatible with Amazon Alexa, Google Home and also supports IFTTT protocols. If you’ve a Nest thermostat in your home, Nuheat Signature can make use of the occupancy sensors (inside Nest) to save energy when no-one is home.
#4 SunTouch Command – Heated Floor Thermostat
Our #4 choice is SunTouch Command, which is a 7 days programmable, touchscreen heated floor thermostat. This model also comes with a floor sensor, and an option to sense air temperature is available. The display color is adjustable, and the font size is big for easy readability.
The adjustable color display and the paintable beauty ring can be set up to match your home decor.
- 3.5-inch touchscreen with a bright display, 7 days programmable and Energy usage monitoring.
- Compatible with electric underfloor heating systems up to 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.
- Up to 3 underfloor heating electric mats can be connected in a single thermostat (provided the combined load is within specifications)
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 hydronic 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)