BoilerFaultCodesYour boiler is failing to detect the flame it has lit, causing it to shut down 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: Incorrect ionisation signal
What causes this fault?
This fault occurs when the boiler's internal sensor cannot detect the flame, even if the burner has ignited successfully. It is usually caused by a carbon buildup on the sensing probe or a loose connection which stops the electrical signal from reaching the control board. In some cases, the control board itself may be failing to process the signal correctly.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like F7 — no call-out fees, no surprises.
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