Low
S.01 on Vaillant Atmomax

Your boiler is currently beginning the process of starting up the fan to clear the system before the heating ignites.

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.

What the manual says

Manufacturer manual

Heating mode fan start-up

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check if the heating or hot water starts normally after a few momentsMonitor the display to see if the code changes to a temperature or another 'S' statusNo action is required as this is a normal operational status message, not a fault

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S.00View →S.02View →S.03View →

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