BoilerFaultCodesYour boiler was working but the flame has unexpectedly gone out, causing the system to stop for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Failure during operation: Flame loss
What causes this fault?
This fault occurs when the boiler successfully senses a flame at first but then loses it while trying to provide heat or hot water. The most common reasons are an unstable gas supply, dirty internal sensors that can no longer 'see' the flame, or a build-up of debris on the burner. Essentially, the boiler's safety system shuts everything down because it can no longer guarantee that gas is being burned safely.
This fault is more common during extreme cold snaps, as a frozen condensate pipe can cause the burner to flood and the flame to fail.
DIY fix possible
Press the reset button (flame symbol with a cross) for 3 secondsCheck that your gas pre-payment meter has creditEnsure other gas appliances like a hob are working correctlyIn freezing weather, check if the white plastic condensate pipe outside is frozen
Find a Gas Safe engineer
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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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