BoilerFaultCodesYour boiler has lost its flame signal during operation, meaning and it can no longer safely heat your water or radiators.
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's internal sensor can no longer detect a steady flame while the system is running. The most common reasons include a buildup of carbon on the sensing probe, a failing gas valve that isn't providing enough fuel, or an unstable electrical signal that causes the safety system to shut the boiler down.
This fault is more common in extremely cold weather, as freezing temperatures can affect the external flue pipes and cause consistent flame instability.
DIY fix possible
Check that your gas emergency control valve is in the 'on' position and you have credit on your gas meter.Inspect the outdoor condensate pipe for signs of freezing or blockages if the weather is very cold.Press the Reset button for two seconds to see if the system reignites.
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A boiler cover plan would cover faults like F2 — 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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