High
Green LED flashing on Saunier Duval Semia Condens F30 E

Your boiler has lost power or has an electrical fault, meaning it cannot start up to provide heating or hot water.

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

Check the 230 V electrical supply circuit; connector 230 V across L and N; PCB fuse blown; PCB faulty

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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