BoilerFaultCodesYour boiler is struggling to stay lit because the small starter flame is being blocked by a buildup of soot or debris.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Blocked pilot injector.
What causes this fault?
This fault occurs when the small tube that delivers gas to the starter flame becomes restricted by tiny particles of soot or dust. Without a strong enough pilot flame to heat the safety sensor, the boiler will automatically shut down to prevent gas from leaking into the room. The most common reason is simply a buildup of debris over many years of operation which eventually chokes the gas supply to the burner.
This issue often comes to light in autumn when the boiler is switched back on after being idle during the summer, allowing dust to settle and harden in the injector.
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 A(4) — no call-out fees, no surprises.
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