BoilerFaultCodesYour boiler is trying to start up but has detected an issue with the air flow or the internal fan system, preventing it from lighting safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Lighting Sequence - Fan/APS
What causes this fault?
This fault occurs when the boiler's internal computer tries to start the fan but cannot confirm that air is moving through the system safely. The most common reasons are a buildup of dirt in the small plastic tubes inside the casing, a mechanical failure of the fan motor, or a sensor that has stopped correctly reporting the air pressure.
This issue often crops up during the first cold spell of autumn when the fan has been sitting idle all summer and struggles to spin up to the required speed.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like LED 1 (RESET) Slow Flashing (2Hz), LED 2 (BURNER LIT) Fast Flashing (8Hz) Simultaneous — no call-out fees, no surprises.
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