High Information
S.1 on Vaillant ecoTEC Plus 615

Your boiler is preparing to ignite but is stuck at the stage where the internal fan is spinning up to clear the combustion chamber.

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 running

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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Related fault codes

F.32View →S. 2View →S. 3View →

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