Low
S.25 on Vaillant Atmomax

Your boiler is currently cooling itself down after providing hot water and will be temporarily unavailable for a few minutes.

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 or fan overrun error

DIY fix possible

Wait for 5 to 10 minutes for the boiler to complete its cooling cycleCheck if the fault clears automatically once the internal temperature dropsEnsure your room thermostat is not set higher than necessary

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Related fault codes

S.20View →S.24View →

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