High Lockout
E05 on Keston C36

Your boiler has stopped working because the internal fan, which safely exhausts fumes, is not spinning correctly or cannot be detected by the system.

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 failure – boiler cannot detect fan rotation – check fan operation and both connectors onto fan

What causes this fault?

This fault occurs when the boiler's control system loses communication with the fan or detects that it isn't spinning at the required speed. The most common reason is a mechanical failure of the fan motor or an electrical issue where the wires connecting the fan to the main circuit board have become loose or damaged.

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

E04View →E07View →

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