Start with the numbers that matter

Most UK households are genuinely comfortable with a living room sitting somewhere between 18°C and 21°C, and bedrooms a degree or two cooler than that. It's a narrower range than many people assume, and it's exactly where the savings hide. Every degree you shave off your target trims roughly 5–10% from your heating use across a typical heating season, because your boiler or heat pump simply has less work to do to hold the room at that level.

A home that idles at 22°C all evening can usually drop to 20°C with almost nobody noticing, particularly once you're used to a jumper rather than a t-shirt in January. If someone elderly, very young or unwell lives with you, keep their main room nearer 21°C and take the savings from elsewhere in the house instead.

Build a schedule around how you actually live

A programmed thermostat beats fiddling with a dial twice a day. Set the heating to come on about 30 minutes before your alarm, and to drop back about 30 minutes before you leave the house. Bring it up again shortly before you normally get home, then let it ease down an hour before bed.

Sleep is where a cooler setting pays off twice over: most people sleep better at 16–18°C, and a bedroom held there all night uses noticeably less energy than one kept at living-room temperature. If you're away, don't switch the heating off completely in winter — set it to 12–15°C as frost protection and leave the internal doors open so air can circulate.

The old advice about leaving the heating on low all day rarely stacks up for a gas boiler in a reasonably insulated home. Timed heating shaped around your actual occupancy is usually cheaper. Heat pumps are the exception, and we'll come to those shortly.

Get the most from thermostatic radiator valves

Your main thermostat sets the overall target; thermostatic radiator valves (TRVs) let you fine-tune each room. Use them properly and you stop paying to heat spaces nobody is sitting in.

• Living room: TRV at 3, roughly 20–21°C
• Bedrooms: TRV at 2, roughly 18°C
• Bathroom: TRV at 3, but only for the hours you use it
• Spare room or study: TRV at 1, or off with the door closed
• Hallway and landing: TRV at 1–2, unless your main thermostat lives there

Keep curtains and furniture clear of the valve head, or it will read the cold rather than the room and keep calling for heat. Bleed your radiators once a year at the start of autumn — trapped air makes every setting work harder than it needs to.

Watch where your thermostat sits

Placement quietly undermines more heating systems than any other single issue. A thermostat in a draughty hallway will keep the whole house warmer than you want, while one above a radiator, in direct sun, beside a cooker or next to an external door will read the wrong temperature and switch off too early.

If you can, move to a wireless or smart thermostat and site it in the room you use most, at roughly seated height and away from heat sources. If yours is fixed in a cold spot, nudge your target down a degree and judge comfort by the rooms you actually occupy.

Turning it up higher won't heat the room faster

This is the most common thermostat myth in the country. Cranking the dial to 30°C doesn't warm the room any quicker — the boiler fires at the same rate and simply overshoots your real comfort level, wasting heat and money before the system catches up.

The same goes for opening a window when a room feels stuffy rather than turning the TRV down, and for heating empty rooms "so the house doesn't get cold". Insulation, draught-proofing around doors and letterboxes, and thick curtains do more for comfort than any thermostat setting ever will.

Pairing good settings with renewable power

If you have solar panels, a home battery or a time-of-use tariff, your thermostat becomes a timing tool as well as a comfort one. Run the dishwasher, washing machine and immersion heater in the middle of the day when generation is strongest, or overnight when power is cheapest, and let your heating follow the same logic.

Heat pumps behave differently from boilers and reward a gentler approach: lower flow temperatures, longer steady runs, and small setbacks of just 1–2°C at night rather than switching the system off entirely. Big overnight drops force the pump to work hard to recover in the morning, which costs more than it saves. If you have a smart tariff, preheat the house in the cheaper afternoon hours so you're not pulling expensive electricity during the evening peak.

None of this requires a dramatic change. Move your daytime setting down a degree, set a sensible overnight temperature, sort your TRVs room by room, and let your schedule do the rest.