BoilerFaultCodesYour boiler has stopped working because its internal fan is spinning faster than it should, which has caused the system 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: Fan speed too high
What causes this fault?
This fault occurs when the boiler's control system detects that the internal fan is spinning at an abnormally high rate or at an inconsistent speed. The most common reason is a communication error between the fan and the main circuit board, or a blockage in the air tubes that prevents the system from accurately measuring air pressure. For safety, the boiler shuts down to prevent incorrect combustion levels.
This fault can sometimes be triggered during periods of high winds, as strong gusts entering the flue pipe can interfere with the fan's rotation and pressure readings.
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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