BoilerFaultCodesYour boiler has lost its flame while running and cannot manage to restart itself, likely due to a temporary interruption in the gas supply or a component failure.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame goes off during operation and subsequent ignition attempts failed: Gas supply temporarily stopped, ignition transformer has spark failure, faulty earthing of appliance
What causes this fault?
This fault occurs when the boiler’s flame is lost while it is already running, rather than failing to start initially. It is usually caused by a temporary drop in gas pressure, a build-up of debris on the ignition components, or an electrical fault that prevents the boiler from detecting its own flame. When the system can no longer confirm a stable flame is present, it shuts down as a safety precaution.
This fault is more common during extreme cold spells, as freezing temperatures can lead to blocked condensate pipes or external gas meter issues that restrict gas flow.
DIY fix possible
Check if other gas appliances, like a hob, are working to ensure gas is reaching the property.If you have a pre-payment meter, check that you have sufficient credit.Press the reset button (indicated by a flame symbol with a cross) for one second to see if the boiler restarts.
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 F.29 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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