High
C6 on Worcester Bosch Heatslave

Your boiler has stopped working because the internal fan that clears out exhaust gases is spinning too slowly or is not communicating with the system.

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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