BoilerFaultCodesYour boiler was lit but the flame has gone out unexpectedly, which has caused the system to stop working 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: Flame loss
What causes this fault?
This fault occurs when the boiler successfully ignites but cannot maintain the flame, leading the system to shut down for safety. The most common reasons include an inadequate gas supply, debris on the burner, or a faulty sensor that can no longer detect that the flame is actually lit.
This fault is more common during extreme cold snaps, as freezing temperatures can cause the external gas regulator to stick or the condensate pipe to freeze and back up.
DIY fix possible
Check that your gas emergency control valve is open and you have credit on your gas meterPress the 'Reset' button (indicated by a flame with a cross through it) for five secondsDuring freezing weather, check if your external white plastic condensate pipe has frozen and thaw it with warm water
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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