Smart home thermostats have come a long way since they first launched. Originally they were just a thermostat that controlled the on and off functions of your boiler. They promised various levels of savings compared to a traditional thermostat, but in reality, they were still quite inefficient in many areas.
Then came zoned heating, Genius Hub was one of the first to adopt this technology and this introduced smart thermostats that allow you to control the radiator valve too. With these, you can then control your home on a room by room basis, so in my house, I can have my office warm throughout the day while keeping the rest of the house cool.
The latest improvement with smart heating systems is the ability to have more control of the boiler via OpenTherm. OpenTherm is a communication standard that allows thermostats to speak to the boiler and control the temperature of the water.
In older boilers, the radiator temperature is set, when the boiler fires up it fills the radiators with the warm water until the room hits the target temperature and the valve shuts off. The boiler will also switch off if that is linked to a room thermostat that hits the target temperature.
With the water being a much higher temperature than the room temperature, a room will warm up past the target temp, then switch off the valve/boiler allowing the room to cool. So a room has peaks and troughs with heating, which is not ideal. It can quite often lead to people setting a thermostat too high, so they don't suffer the effects of the dropping temperature.
OpenTherm allows the thermostat to adjust the boiler's water temperature setpoint (the ‘Control Setpoint'). This, therefore, allows the thermostat to heat up a room to the set temperature and keep it there.
Generally, the lower the temperature of the water the higher the efficiency of heating it is. With modern condensing boilers you need to have the output heat higher than the dew point of the water which is around 55-degrees.
So if you have invested in a fancy new condensing boiler with OpenTherm what are the compatible smart home thermostats?
OpenTherm Compatible Smart Thermostats
|tado° Wireless Smart Thermostat Starter Kit V3+ with Hot...||£199.00||Buy on Amazon|
[Update] I previously listed the Hive Active Heating 2 but have recenlty been informed this lacks OpenTherm
One notable omission from the above the list is Genius Hub which I use personally. I am led to believe that this will be implemented soon.
OpenTherm Compatible Smart Thermostat Recommendation
I would personally opt for a heating system with zoned radiator control. You don't need them on every radiator, but it can help you cut back on heating is less frequently use rooms.
Therefore my recommendation would be Tado because it has zoned heating and is one of the cheapest smart heating solutions on the market.
The tado° Smart Thermostat – Starter Kit V3+ with Two Add-on Smart Radiator Thermostats costs just £159.99 and each radiator valve is £49 or £89 for a 2 pack and £149 for a quad pad.
In comparison, Hive is £129 just for the Thermostat then £53.99 per radiator valve.
Last update on 2021-01-15 / Affiliate links / Images from Amazon Product Advertising API