High
F9, L9, F8 or L8 on Ideal Compact

Your boiler's internal computer has lost its settings or suffered an electrical failure, meaning it can no longer communicate with the rest of the unit.

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

Printed circuit board (PCB) unconfigured or fault

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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Related fault codes

F7View →L2View →F1View →

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