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

radiant floor heating thermostat
Honeywell – Electric floor heat 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.

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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)

Thermostat for radiant heat
Nuheat Home – Radiant Floor Heat Thermostat

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.

NuHeat - Check Price

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.

Highlights:

  • 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

 

In floor heating thermostat with WiFi
Nuheat Signature – WiFi Floor Heat Thermostat

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.

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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

Electric underfloor heating thermostat
SunTouch Command – Floor Heat 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.

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The adjustable color display and the paintable beauty ring can be set up to match your home decor.

Highlights:

  • 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)
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7 Comments

  1. Hi, Thanks for the article. I currently have hydronic radiant floor heat under hard wood; it uses little Watts Radiant (P-3285) thermostats that allow you to set air temperature and also have a floor sensor allowing you to set a maximum and minimum floor temperature. They aren’t programmable. I’d like to replace them with Nest thermostats in the rooms that I use the most so I can control those remotely (and leave all the other ones at a low temperature generally). Is the floor sensor important to have? I noticed that most thermostats DO NOT have floor sensors. There are a few Honeywell (that aren’t WIFI) and some by TekMar (now owned by Watts).

    Thanks
    AJ

    • Mathew Kevin Reply

      A floor sensor is not necessary, unless you have a very sensitive feet. If your feet is sensitive to minute temperature changes, please go for an underfloor heating thermostat with floor sensor.

      • Haha. Thanks for the advice. I think the floor temperature sensor is to set min/max (as a safety feature) to make sure that the floors don’t get too hot (or cold) trying to achieve an air temperature. Not as much for sensitive feet. 🙂

  2. craig morton Reply

    We added a 24×24 ft guest room off the side of our house a few years ago. It was built on a concrete slab and we had the radiant heat put into the concrete with the plastic tubing. Would you say the #1 Aube by Honeywell – TH140-28-01-B/U above is the best thermostat to use? We live in New Hampshire and in the spring and fall it is very difficult to control the temperature in that room because once that 24x24ft block on concrete it heated up, it always overshoots the desired temperature.

    • Mathew Kevin Reply

      @Craig, Unfortunately I can not pin point to one single model, as different regions vary. Currently, Aube and Nuheat are two good models available in the market for underfloor heating. You may try querying in some regional forums/groups to see what people are buying in your area. Thanks!

  3. Hi Matt,

    I have a situation where my radiant floor sensors/wiring (not sure which) have been damaged and I can no longer get any reading nor control at the T-stat (I have the tekmar t-stat package). Are you aware of any sensor package that i could just affix to the supply and return line that could give me an differential that I could calibrate to the approximate surface temp? ofcourse factoring flow rate and the floors thermal resistance.

    Regards,

    Robert

    • Mathew Kevin Reply

      @Robert, I’d say you better hire a professional to fix the sensor/wiring problem.

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