BoilerFaultCodesWhat the manual says
Manufacturer manualfan overrun
From this model's manual
Verified against the Glow Worm Flexicom 18sx installation & service manual, page 47.
What causes this fault?
This fault occurs when the boiler's control system detects that the fan is still spinning even after the heating cycle has finished and the cooling period should have ended. The most common reason is a communication error between the main circuit board and the fan, or a mechanical stickiness within the fan motor itself that prevents it from stopping correctly.
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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