Before spending thousands on a new heat source, control the one you have. Proper controls — room thermostat, TRVs, scheduling, and for modern boilers load/weather compensation — typically cut heating bills 5–15% for a fraction of the cost of any other measure.
1. Room thermostat + programmer — the legal minimum on new installs; if you genuinely lack one, this is step one. 2. TRVs on radiators — room-by-room temperature limits, £10–£25 per valve plus fitting. 3. Smart thermostat (£120–£250) — scheduling people actually use, geofencing, remote control; savings come from better behaviour, not magic. 4. Load/weather compensation — modulates boiler flow temperature to conditions; on condensing boilers this is where real efficiency hides, keeping the boiler in condensing mode far more of the time.
Honest numbers: a smart thermostat saves most where heating was previously badly scheduled — typically 5–10%. TRVs and zoning save by not heating empty rooms — a few percent more. Compensation controls on a compatible condensing boiler can add another 5–10% by cutting flow temperatures. Stacked on a typical £1,200 gas heating bill, £80–£180 a year is realistic — against a total spend often under £500.
Controls matter differently with a heat pump: steady low-temperature operation beats on/off cycling, so aggressive setback schedules can cost money rather than save it. Weather compensation is usually built in — commissioning it properly (flow temperature curve) is the single biggest running-cost lever. See our heat pump running costs guide.
Heating controls are on the ECO4 measures list — typically installed alongside other measures for eligible households until 31 December 2026. Privately, controls fitted with a qualifying energy-saving installation can fall under the 0% VAT treatment; standalone smart thermostats are cheap enough that VAT rarely changes the decision.
Facts checked 21 August 2026. We link to official sources and show when facts were last verified. If a scheme changes, we update the page.
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