This guide explains how to lower your gas bill with changes to boiler settings, heating controls, insulation and hot water use. Gas heating and hot water make up most of the energy used in a typical UK home, so small changes here have a bigger effect than almost anything else.
Quick answer: Lower the boiler flow temperature to around 60°C, set the thermostat a degree lower, use timers and radiator valves so you only heat rooms you use, cut draughts, and shorten showers. At the October to December 2026 cap of 7.97p per kWh, every 1,000 kWh of gas saved is worth about £80.
Where does your gas go?
In most UK homes with a gas boiler, space heating uses the biggest share of gas, followed by hot water, with cooking a small part. Ofgem’s medium usage figure for gas is 9,500 kWh a year, which costs about £757 in units at the October to December 2026 cap of 7.97p, plus the standing charge of 29.68p a day.
12 ways to cut your gas bill
- Lower the boiler flow temperature. A condensing boiler is most efficient when the water returning to it is cool. Setting the radiator flow temperature to around 60°C, or lower in mild weather, lets it condense more of the time.
- Turn the room thermostat down by 1°C. The Energy Saving Trust estimates this is one of the simplest heating savings for a typical home.
- Use a timer. Heat the house when you are in and awake, not all day.
- Use thermostatic radiator valves. Set lower levels in bedrooms and rooms you rarely use.
- Bleed radiators. Trapped air makes the boiler run longer.
- Draught-proof doors, windows and floors. Cold draughts make you turn the heating up.
- Top up loft insulation. About 270 mm of mineral wool is the usual recommendation.
- Close curtains at dusk. Heavy curtains reduce heat lost through windows.
- Shorten showers and fit an efficient shower head. Hot water is a big share of gas use.
- Lower the hot water temperature on a combi. 50 to 55°C is often enough for a combi boiler; stored cylinders need 60°C regularly.
- Service the boiler. A well-maintained boiler runs safely and efficiently.
- Compare tariffs. Check fixed deals against the cap using your own annual usage.
What does each change save?
Estimates for a typical semi-detached home with gas heating, at 7.97p per kWh:
| Change | Gas saved per year | Saving |
|---|---|---|
| Thermostat down 1°C | about 1,000 kWh | about £80 |
| Flow temperature to 60°C on a condensing boiler | about 500 to 800 kWh | about £40 to £64 |
| Draught-proofing | about 600 kWh | about £48 |
| Shorter showers, one minute less each | about 400 kWh | about £32 |
These are rough figures; your savings depend on the house, the boiler and how you live.
Is it cheaper to leave the heating on low all day?
Usually not. A home loses heat faster when it is warmer inside than out, so heating it all day loses more energy than heating it only when needed. Our guide to whether it is cheaper to leave the heating on all day explains the exceptions, such as some heat pumps.
Should you switch to electric heating to save money?
Direct electric heating costs 26.32p per kWh against about 9p per kWh of heat from a gas boiler, so it is usually more expensive. A heat pump can match or beat gas because it produces around 3 kWh of heat for each kWh of electricity.
Frequently Asked Questions
What uses the most gas in a home?
Space heating, followed by hot water.
What temperature should my boiler be set to?
Around 60°C flow for radiators in most homes with a condensing boiler, adjusting as needed in very cold weather.
Does turning the thermostat down really save money?
Yes. Each degree lower reduces the heat the home loses.
How can I check my gas use?
Read your meter regularly or use a smart meter display; our gas meter reading calculator converts readings to kWh.
Checked November 2026 by the Solaxyra Editorial Team. Sources: Ofgem: Energy price cap, 1 October to 31 December 2026, Energy Saving Trust: Thermostats and controls, Heating Hub: Boiler flow temperature.