BoilerFaultCodesTechnical description
Heating mode – fan overrun error
What causes this fault?
This fault occurs when the boiler's control board expects the fan to stop spinning after a heating cycle, but it continues to receive a signal that the fan is still rotating. The most common reason is a communication error between the fan and the main circuit board, often caused by a faulty sensor inside the fan or a sticking internal component. In some cases, a damaged wiring harness or moisture on the electronics can prevent the fan from shutting down 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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