Will my gas boiler work in a power cut?

Last checked 28 October 2026. Based on Citizens Advice, Which?, GOV.UK Be Ready and boiler manufacturers.

Why a gas boiler stops

A modern boiler uses electricity for its ignition, fan and controls. Without power it will not light, as a safety feature. Your gas supply and meter keep working as normal; the boiler simply cannot use it. When the power comes back, the boiler should start again, though you may need to reset its clock or timer.

A small number of older boilers may work without power. If you are not sure about yours, check with the manufacturer or a Gas Safe registered engineer before you need it.

What else stops

• Heat pumps and electric storage heaters will not work in a power cut.
• Gas ovens usually will not work, because most modern ones need electricity as a safety feature.
• Gas hobs usually still work, but the spark may not. Light a burner with a long safety match or a gas lighter, on the lowest setting.
• Smart thermostats switch off with the power and usually pick up their programme again when it returns.

Keeping warm safely

• Pick one room to keep warm. Close doors and curtains, and put on layers, a hat and warm socks.
• Keep sleeping bags or spare duvets ready, and hot water bottles if you can boil water on a gas hob.
• Never use a gas cooker or hob to heat a room.
• Never use a barbecue, camping stove or generator indoors or in a garage. They give off carbon monoxide, which can kill.
• Only use a portable gas heater if it is approved for indoor use, and keep the room ventilated.

Carbon monoxide

Fit a battery carbon monoxide alarm (marked EN 50291) in rooms with a fuel-burning appliance. Mains alarms without a battery stop in a power cut. Headaches, feeling sick, dizziness or breathlessness can mean carbon monoxide: get everyone into fresh air and call 999. If you smell gas, call 0800 111 999 (Northern Ireland: 0800 002 001).

Check your home

Find out how long your home would last if the power went off tonight, and what to do about it.