Low
S.15 on Vaillant Atmomax

Your boiler is temporarily cooling itself down after you have used the hot water taps.

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

DHW mode pump and fan overrun

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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Related fault codes

S.07View →S.10View →

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