High Lockout
F3 on Ideal Logic Combi C24 C30 C35

Your boiler has detected an issue with the internal fan, which is preventing the system from safely clearing exhaust gases and starting the ignition 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

Fan Fault

What causes this fault?

This fault occurs when the boiler's control center is unable to communicate with or power the fan that removes exhaust gases. The most common reasons are a complete mechanical failure of the fan motor or a fault in the electronic circuit board that sends the signal to start. Without the fan spinning at the correct speed, the boiler will refuse to ignite for safety reasons.

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 →L2View →

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