High
C6 on Worcester Bosch Junior 28i

Your boiler has detected that its internal fan is not spinning fast enough to safely clear away exhaust fumes, which has caused the system to shut down for safety.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Fan speed too low – the fan lead and connector need checking and may need replacing.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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