BoilerFaultCodesWhat the manual says
Manufacturer manualFan running
From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual.
What causes this fault?
This status occurs when the boiler is attempting to start its ignition sequence but becomes stuck while the fan is spinning. It typically happens because the fan cannot reach the required speed or the boiler's control board fails to receive a signal confirming that the fan is working correctly. This prevents the boiler from safely moving to the next stage of lighting the burner.
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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