Buying guide

How to choose a smart thermostat for a UK home

By COMANORA· Updated 5 November 2026· 8 min read

Draft for owner review — wording and facts to be checked against sources before launch.

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The 60-second answer

Find your heating system. Combi boiler, system boiler, regular boiler or heat pump.
Check for OpenTherm. If your boiler supports it, a thermostat that also supports it can adjust the boiler’s output rather than just switching it on and off.
Look at your wiring. Some mains-powered thermostats need a neutral wire; battery models usually don’t.
Add up the three-year cost. Include any subscription the features you want depend on.

Not sure about any of these? Our boiler compatibility checker walks you through them.

Know your heating system

Combi boiler — heats water on demand, with no hot water cylinder. Very common in UK homes, especially flats and smaller houses.
System boiler — has a hot water cylinder, usually in an airing cupboard, but no water tank in the loft.
Regular (conventional) boiler — has both a cylinder and a cold water tank in the loft.
Heat pump — runs best at lower flow temperatures for longer periods, so it benefits from controls designed for that, such as weather compensation.

If you have a cylinder, you may want a thermostat that can also schedule your hot water.

Check your wiring

Most smart thermostats replace an existing wired thermostat or programmer and reuse its wiring. Before buying:

Switch off the power and look at the terminals on your current thermostat or programmer.
If the product needs a neutral (N) wire, make sure one is present.
If you rent, prefer products whose receiver reuses the existing wiring and can be removed without trace.

If you are not confident with mains wiring, use a qualified electrician or heating installer. Any work on the gas side of a boiler must be done by a Gas Safe registered engineer.

Features worth paying for

Feature	Why it matters	Who needs it
OpenTherm	Lets the boiler run at lower output instead of cycling on and off	Owners of OpenTherm-compatible boilers
Geofencing	Turns the heating down when everyone has left	Homes with irregular routines
Hot water control	Schedules the cylinder as well as the heating	System and regular boilers
Multi-room expansion	Adds smart radiator valves later	Larger homes

Subscriptions

Some brands put features such as geofencing or energy reports behind an optional subscription. Always check which features you actually want and whether they need one. We show the three-year cost on every product page.

Will it save money?

A smart thermostat saves energy mainly by not heating an empty home and by making schedules easier to get right. How much you save depends on your home, your habits and how you controlled your heating before, so we present savings as ranges with the assumptions shown, never as a promise.