Is a smart thermostat worth it?
Where the saving actually comes from, which households benefit and which do not, and what to check before buying.
- Difficulty
- beginner
- Time
- 20 min
- Read
- 2 min
Short answer
The saving comes from heating your house less, not from the thermostat being clever. It benefits irregular schedules and multi-zone homes most, and benefits a well-scheduled existing timer very little.
Smart thermostats are sold on savings figures that assume you are currently heating an empty house. If you already have a programmable thermostat set sensibly, most of that saving has already been taken.
Step by step
- Work out what you have now.No timer at all, a basic timer, or a programmable thermostat used properly? The worse your current control, the more a smart one gains — and the difference is large.
- Be honest about your schedule.Irregular hours, working from home some days, an empty house at unpredictable times — these are where smart control genuinely earns its cost. A fixed routine is served well by a cheap programmable timer.
- Understand where the saving comes from.Heating fewer rooms, for fewer hours, at slightly lower temperatures. The thermostat only makes that easier to do — it does not create savings by itself.
- Consider zoning, which is the bigger gain.Smart thermostatic radiator valves that heat only the rooms in use often save more than the thermostat. That is the feature worth paying for in a larger house.
- Check compatibility before buying.Boiler type, existing wiring, whether there is a common wire, and whether a hot water cylinder needs controlling too. This is where installations go wrong.
- Check what it does without internet.A thermostat that cannot be adjusted during an outage is a genuine problem in winter. Look for local control and physical buttons.
- Factor in installation.Some fit onto existing wiring in twenty minutes; others need an electrician or heating engineer. Get that cost into the comparison.
- Do the cheap things first.Draught-proofing, radiator balancing, thermostatic valves and turning the thermostat down one degree all save money for far less outlay.
Tips
- Turning the thermostat down by one degree typically saves more than any smart feature, and costs nothing.
- The genuine convenience benefit — heating on before you get home, off when you forget — is real and worth something even if the saving is modest. Judge it on that honestly.
- Check whether your energy supplier offers one as part of a tariff. It changes the economics substantially.
Questions people ask
Do smart thermostats actually save money?
They can, mostly where current control is poor or the schedule is irregular. If you already use a programmable thermostat well, the additional saving is small.
What saves more, a smart thermostat or smart radiator valves?
In a larger house, usually the valves — heating only the rooms in use is a bigger lever than optimising when the whole house is heated.