BoilerFaultCodesWhat the manual says
Manufacturer manualfan overrun
From this model's manual
Verified against the Glow Worm Flexicom Cx installation & service manual, page 45.
What causes this fault?
This fault occurs when the boiler's control board detects that the fan is still rotating even though the power to it has been cut. The most common reason is a communication error between the fan and the main circuit board, often caused by a failing fan motor or moisture affecting the sensitive electronic sensors.
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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