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

#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.

Technical Specifications to keep in mind:

  • 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.

Highlights:

  • 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.

Highlights:

  • 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)
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