BoilerFaultCodesYour boiler's fan is spinning faster than it should, which has caused the system to shut down for safety purposes.
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 a higher speed than required for safe combustion. It is typically caused by a faulty sensor within the fan motor itself or a communication error from the main control board, which prevents the boiler from regulating the airflow 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 C6 — no call-out fees, no surprises.
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