BoilerFaultCodesYour boiler has lost its flame while running, meaning it is not getting enough gas or the spark is failing to keep the burner lit.
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 starts but then unexpectedly loses its flame while it is trying to provide heat or hot water. The most common reasons are a dirty or worn-out sensor that can no longer 'see' the flame, or an inconsistent gas supply that causes the burner to go out. It can also be caused by debris blocking the burner or a failing component that manages the electrical spark.
This fault can be more common during very cold snaps if the gas meter regulator freezes or if the increased demand for gas in the neighborhood causes a drop in pressure.
DIY fix possible
Check if your gas meter has credit (if on a prepayment meter)Check if other gas appliances, like a hob, are working to confirm gas supplyReset the boiler by turning the mode knob to 'RE' and then back to the desired settingEnsure the external condensate pipe has not frozen if it is winter
Find a Gas Safe engineer
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A boiler cover plan would cover faults like Ln — 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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