Fan Fault High

Keston Fan Fault Fault Code

Also written as FANFAULT — same fault.

The Keston Fan Fault fault code means: your boiler has stopped working because it cannot properly clear exhaust gases, so it has shut down as a safety precaution to prevent dangerous fumes from building up.. It appears on 5 Keston models in our database.

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: Check Fan Wiring, Check Fan
Typical repair cost £250-450 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Keston models that show the Fan Fault fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Keston Fan Fault fault code information on this page is sourced and cross-checked against the official Keston service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026