Low
S.01 on Vaillant Home System

Your boiler is currently preparing to start the heating cycle by running its internal fan to clear out any residual gases.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Heating mode: Advance fan operation

DIY fix possible

No action is required; this is a normal status message and not a breakdown code.Wait a few moments for the boiler to move to the next stage of operation.Check that your thermostat is calling for heat if the boiler stays on this code for a long period.

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Related fault codes

S.02View →S.03View →S.04View →

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