BoilerFaultCodesYour boiler's fan is spinning too fast or the control board cannot regulate its speed, preventing the boiler from starting safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fan speed too high
What causes this fault?
This fault occurs when the boiler's internal computer detects that the fan is spinning at an uncontrollable or dangerously high speed. The most common reason is a communication failure between the fan motor and the control board, often caused by worn-out electronics or loose internal wiring. Because the fan is responsible for clearing waste gases safely, the boiler will prevent ignition to avoid a potential safety risk.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like C6 — no call-out fees, no surprises.
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