High
H09 on Worcester Bosch Greenstar i

Your boiler has lost its connection to the water pump that circulates heat around your home, meaning it cannot safely 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

Communications to the pump has failed. The feedback signal has been lost, possible causes are electrical connections loose or disconnected, pump has been replaced with an incorrect type.

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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