High
360 on Worcester Bosch Greenstar i

Your boiler's computer module does not match the internal controller, meaning the system cannot communicate properly 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

HCM invalid (The inserted HCM does not correspond with the control box)

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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