High
Safety system failure on Halstead Finest 100

Your boiler's internal computer has encountered a critical error during its automatic safety checks and cannot safely operate, requiring a professional to investigate.

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

Failure of internal self checking system • Check PCB

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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