High Lockout
F3 on Ideal Logic Combi ESP1

Your boiler has stopped working because the internal fan, which safely exhausts gases produced during heating, is not running correctly.

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 system detects that the fan is not spinning at the required speed to safely clear exhaust gases. The most common reasons are a mechanical failure of the fan motor itself or a communication issue where the main circuit board is unable to send power or signals to the fan.

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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