Low
S.10 on Vaillant Atmomax

Your boiler has detected that a hot water tap is turned on and is preparing to heat water for you.

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

Hot water demand via impeller sensor

DIY fix possible

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

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Related fault codes

S.11View →S.14View →

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