BoilerFaultCodesYour boiler has shut down and stopped providing heating and hot water because it has detected a safety issue, likely involving gas supply, air flow, or overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: No domestic hot water or central heating. Check: Water pressure, shortage of air or gas, faulty temperature sensor, overheating, wrong flue length, or air pressure switch connections.
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that a vital element needed for combustion, such as gas or air, is missing or at the wrong temperature. It is often triggered because the boiler cannot safely vent exhaust fumes or because a component has detected that the unit is getting too hot.
This issue often surfaces during the first cold snap of autumn when the boiler is pushed to run at higher temperatures after being idle all summer.
DIY fix possible
Check if the water pressure gauge is between 1 and 1.5 barCheck if other gas appliances in the home are workingEnsure the external flue pipe is not blocked by debrisPress the reset button once
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like A flashing warning light on control panel — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm 23C is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.