High
EH 258 on Worcester Bosch Hideaway

Your boiler's internal computer or control unit has suffered an electrical failure and can no longer manage the heating process.

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 – HCM or 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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