I asked experts the ideal thermostat temperature – they gave the same number

With the UK firmly in the grip of a cold and wet winter, we are all looking for ways to keep our central heating costs as low as possible, especially since it now costs approximately £600 more a year to warm our properties than it did in 2022.

While the temperature has not been too cold in recent days, considering it’s February, it is forecast to drop to 0°C by the end of next week, with snow forecast for some areas. 

The positive news is that there are ways to reduce your heating expenses without spending money, potentially saving you considerably more than £100 each year – you can see five easy ways to do that here. You can also try the classic towel method and the candle technique. I sought advice from dozens of heating and thermostat experts on how to keep bills low and one thing they agreed on was the temperature to set your thermostat.

Nick Duggan, managing director at The Radiator Centre, said: “The ideal temperature for a room is between 18-21°C. Every extra degree adds around 10% to the average heating bill so it’s important to ensure your radiators are working as efficiently as possible.”

There’s also a critical mistake to avoid, which many of us do. A spokesperson for Octopus Energy said using your thermostat  “like an on/off switch or ‘boost’ button can actually waste energy, as the system works harder to reheat the space. You’ll stay comfier – and use energy more efficiently – by setting it to come on only when you need it and leaving it steady between 18-21°C. Turning it down by just one degree could save up to £145 a year”.

Fiona Peake, household finance expert at Ocean Finance, says: “Many Brits are cranking the thermostat up high to ‘heat the home faster’. In reality, your boiler works at the same pace no matter what temperature you set. All you are doing is overshooting the temperature and wasting energy. Instead, set the thermostat to the lowest comfortable setting, usually around 18-21°C, and let it run steadily.”

Gav Murray, Hive heating director, said: “Hive advises people to set their main thermostat between 18°C and 21°C… For an average household, lowering the temperature by just one degree could save as much as £115 a year.”

Adam Knight, lead engineer at BOXT, said: “Keep it simple and steady. Set the thermostat to a realistic target, about 18-20°C for most homes during the day, with a small adjustment for nighttime, usually around 16-17°C, rather than switching off.”

Ricky Sharma of Engineering Real Results (ERR), a training organisation for trades such as heating engineers and plumbers, said: “Most homes are comfortable at between 18°C and 21°C, so if you usually keep it higher try turning it down a little and adding an extra layer of clothing instead. Lowering your thermostat by just 1°C could cut your bill by around 10%, according to the Energy Saving Trust, which equates to an average of £120 a year back in your pocket.”

Matthew Sheeran from Money Wellness, an organisation commissioned by the government’s Money and Pensions Service to provide free money saving, debt and income maximisation advice, said: “Turning your thermostat down by 1°C can cut bills by up to 10% and using a timer to heat your home only when needed avoids wasted energy.”

• Draught-proof your home by checking windows, doors and chimneys
• Use your thermostat properly: aet it to between 18-21°C and don’t crank it up higher when you come home to an empty house as this does not make it heat faster
• Only heat the rooms you’re using and turn off the radiators in the rooms you’re not
• Use your boiler and radiators properly: an old and worn-out boiler will be working much harder to heat less effectively. Bleed any radiators that aren’t as warm as you’d expect
• Keep yourself warm first using clothes, blankets and even a hot water bottle to keep yourself warm and needing to spend less on heating your home.