High
FAIL POINT A on Worcester Bosch Greenstar 25Si

Your boiler is not receiving any power, meaning it cannot provide heating or hot water until an electrical supply is restored.

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

Facia on/off switch turned off or no 230V AC live supply across Terminal ST12 pins L and N or Fuse F1 blown.

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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