High
F0 242 on Worcester Bosch Danesmoor

Your boiler's main internal computer has developed a communication fault and can no longer control the heating process safely.

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

Control box or the heat control module (HCM) is defective – the HCM and control box connections need to be checked

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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