High
FAIL POINT K on Worcester Bosch Greenstar 25Si

Your boiler is struggling to ignite because the internal gas system isn't communicating correctly, meaning you currently do not have 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

Gas valve mode switch not set to 'NORM' or Water temperature low/gas pressure incorrect. Possible blue wire harness 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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