BoilerFaultCodesYour boiler has detected a flame signal when there shouldn't be one, or it is running too hot to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Permanent fault. False flame signal, short-term fluctuation of the mains, ionization current present even though there is no flame, the burner remains very hot (CO2 too high) or defective gas/air unit.
What causes this fault?
This fault occurs when the boiler's internal sensors detect a flame after the heating cycle has finished or identify that the burner assembly is dangerously overheating. The most common reason is a sensor incorrectly reporting a signal due to moisture or carbon buildup, or a gas valve that is failing to close fully and let the burner cool down.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E.04 – .12 — 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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