UK households spend an average of around £1,500 per year on gas and electricity, with heating accounting for the majority of that figure. Smart heating products are widely marketed as a straightforward solution, but the savings they deliver vary considerably between households — and between products within the same category.
| Product type | Typical cost (installed) | Estimated annual saving | Best for |
|---|---|---|---|
| Smart thermostat (basic) | £100–£180 | £75–£150 | Households heating the whole home to a fixed schedule |
| Smart thermostat with multi-zone | £200–£350+ | £150–£250 | Homes with multiple rooms heated to different temperatures |
| Smart radiator valves (TRVs) | £15–£40 per radiator | £50–£120 (varies) | Households heating rooms they don't all use simultaneously |
| Home energy monitor | £30–£70 | Indirect — behaviour dependent | Anyone wanting clearer visibility of consumption by appliance |
Smart thermostats: what actually drives the saving
The energy saving from a smart thermostat comes primarily from two features: the ability to set more granular schedules (heating only when occupants are present rather than on a basic on/off timer) and the auto-away or geofencing function, which reduces heating when the home is empty. Studies suggest the scheduling benefit is real but modest for households already using a basic programmer; the bigger gains come in homes that previously had no schedule at all, or that heated consistently regardless of occupancy.
Smart radiator valves and zone control
Smart TRVs allow individual radiators to be set to different temperatures and schedules, which is most valuable in households where different rooms are used at different times. A bedroom left at 16°C during the day and raised to 18°C at 10pm uses considerably less energy than one maintained at 20°C throughout. The payback period for a full-home TRV installation depends on how many radiators you have and how much unused heating time exists in your current routine.
Before buying: four things worth checking
- Is your boiler compatible with the smart thermostat you're considering? Most modern combi boilers are, but some older systems are not.
- Does your broadband router have a strong enough signal where the thermostat will be installed?
- Are you heating rooms you rarely use? If yes, zone control will deliver more benefit than thermostat-only control.
- Do you have a heat pump or electric heating? Many gas-focused products don't integrate well with non-gas systems.
For households already on a reasonable boiler with a basic programmer, a smart thermostat upgrade tends to deliver a payback period of 12–24 months assuming normal use. For households currently using no scheduling at all, the payback can be considerably faster. The key variable in almost every case is behaviour — a smart thermostat that is overridden manually or set to constant-on mode delivers no benefit whatsoever.