High
F3 on Keston System S30

Your boiler's internal fan is not spinning or communicating correctly, preventing the system from safely clearing gases so it has shut down for safety.

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

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 →L2View →

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