High Lockout
10 on Glow-worm Xtrafast 96

Your boiler has detected that the fan, which safely removes waste gases from the appliance, is not spinning correctly or has lost communication with the main control board.

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 board sends a signal for the fan to start, but it fails to reach the required speed to safely clear waste gases. The most common reasons are a build-up of debris causing the motor to seize, or an electrical failure within the fan's internal circuitry that prevents it from communicating with the boiler.

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

F2View →F3View →

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