High
4 red flashes on Baxi Suprima 115

Your boiler's internal fan is failing to start or run at the correct speed, which means the system cannot safely clear waste gases and has shut down as a precaution.

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 fault

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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Related fault codes

3 red flashesView →5 red flashesView →

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