If your home is having a single stage heating system (like a gas furnace) without any cooling function, you simply need a “heat only thermostat” to control the heating system. A heat-only thermostat is designed to perform the basic function of regulating room temperature by controlling the heating system (be it a single stage furnace or a heat pump). Usually, a basic heat only thermostat will be having only two switch controls – 1) an On/Off switch and 2) temperature adjustment buttons.
When put to “ON” position or “Heat” position (some thermostats mark ‘On’ as ‘Heat’), the thermostat will turn ON the furnace/heating system and keep it active until the set temperature is achieved. The ‘adjustment buttons’ can be used to increase/decrease the temperature to your desired level.
There will be only 2 terminals for a heat-only thermostat, marked ‘R’ and ‘W’. You only need to make two connections between your heating system and the thermostat.
Note 1: Some single-stage heating systems have a fan to distribute heat faster. For such systems, heat only thermostats with a fan switch option is available. These thermostats will have 3 terminals usually, marked ‘R’, ‘W’ and ‘G’; where ‘G’ terminal is to connect the fan of the furnace.
Note 2: Heat only thermostats are also known as ‘2 wire thermostats’. You may read our guide on 2 wire thermostats, which also covers 2 wire single pole thermostats for line voltage systems.
Best Heat Only Thermostats
Now let’s see all the popular ‘heat only thermostat’ models out there. As mentioned above, a heat only thermostat is basically a 2 wire thermostat with two terminals ‘R’ and ‘W’, which is suitable to regulate a single stage heating system (without any cooling option).
Note: To regulate a single-stage heating system, you can actually use any thermostat that supports single stage wiring. For example, Smart thermostats like Nest, Ecobee, and WiFi thermostats like Honeywell RTH9585WF, Emerson Sensi – all support single stage wiring. You just need to connect the ‘R’ and ‘W’ terminals of these thermostats and leave all other terminals not connected. So if you want a technologically advanced thermostat with smart features, internet connectivity, and smartphone-based control, you better choose one above rather than a basic heat only thermostat.
#1 Honeywell TH1100DV1000 Heat Only Thermostat
This is a basic heat only thermostat model from Honeywell, with a temperature range of 40 deg F to 90 deg F to choose from. It has only 3 buttons, an Off/Heat button on the side and an up/down button on the front to adjust the temperature range. This model has a square-shaped, backlit LCD display, which displays temperature in an easy-to-read format. TH1100DV also provides a compressor protection feature for the heating system.
If you’re using this model in the garage, a mode is available where temperature can be ranged from 35 deg F to 90 deg F.
#2 Emerson 1E78 Heat Only Thermostat
1E78-140 is one of the best-selling non programmable heat only thermostats from Emerson. This model is compatible to be used with single stage heat only systems, single-stage heat pumps, and millivolt systems. The display is a rectangle-shaped LCD, with a backlight.
1E78 is designed in such a way as a perfect upgrade to an old mechanical thermostat. The body is designed to cover any wall markings by a mechanical thermostat (old models) and in most cases, you don’t need an extra wall plate.
#3 LuxPro PSD010B Heat Only Thermostat
If you need a third choice, PSD010B from LuxPro is a popular nonprogrammable heat only thermostat. This model is compatible with all heat only single stage systems. If your system has a fan, LuxPro has a variant of this same model named PSD010BF – which has additional fan control.
The display is rectangle-shaped, with a backlight, and it displays only the set temperature. The base model PSD010B has only 3 buttons, an On/Off button and an up/down control. The model with a fan (PSD010BF) has 4 buttons, an additional button on the side to control fan operation.