High
F9 on Ideal Logic Max Heat 2

The computer brain inside your boiler has lost its settings or suffered a hardware failure, meaning it cannot operate safely or effectively.

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.

What the manual says

Manufacturer manual

PCB UNCONFIGURED OR FAULT. SEE SECTION 3.18. IF FAUL PERSISTS REPLACE PCB

From this model's manual
Verified against the Ideal Logic Max Heat installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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

F1View →F2View →F3View →

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