High
FAIL POINT F on Worcester Bosch Greenstar 25Si

Your boiler has detected that it is in an area that is too cold, so it has effectively entered a protective standby mode to prevent its pipes from freezing.

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

Boiler in very cold environment (less than 5°C) - Autofrost stat mode. Possible damp control board.

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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