Smart heating controls

What counts as a "smart" heating control

"Heating controls" covers a ladder of devices, from basic to connected:

• Programmer / timer — turns heating on and off to a schedule.
• Room thermostat — holds the home to a target temperature so the boiler isn't running when it's already warm enough.
• Thermostatic radiator valves (TRVs) — set different temperatures room by room.
• Smart thermostat — a connected room thermostat you control from your phone, that can learn your routine, respond to whether anyone's home, and let you turn the heating down from the bus when your plans change.
• Smart TRVs / zoning — connected valves that heat individual rooms on their own schedules, so you stop paying to heat empty rooms.

A "smart" system is simply controls you can see and adjust remotely, with automation that removes the human error — the forgotten timer, the radiator left on full in a spare room.

How the saving actually happens

It is worth being precise, because a lot of marketing isn't. A smart thermostat does not make your boiler or heat pump more efficient. It saves money in three honest ways:

• Heating less often — schedules and presence detection mean the heating isn't running for an empty house.
• Heating to a lower temperature — turning the target down by 1°C typically trims heating use by a few percent, and smart controls make that easy to set and keep.
• Heating fewer rooms — zoning stops you warming bedrooms during the day or a home office at the weekend.

That's where the Energy Saving Trust's ~10% figure comes from, and it's why the saving depends far more on how you use the controls than on which brand you buy.

Where smart controls help most

The bigger the house, the more variable your routine, and the more rooms you don't use all day, the more there is to save. A small, consistently occupied flat has less to gain than a four-bedroom house where two rooms sit empty on weekdays. If you already run a tight schedule with good TRVs, a smart thermostat is a convenience upgrade more than a savings one — and that's fine, as long as you buy it knowing that.