Low
S.27 on Vaillant aquaPLUS

Your boiler is briefly running the pump after heating your hot water cylinder to move excess heat away and protect the internal components.

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

Pump over run (store charging)

DIY fix possible

Check that at least one radiator valve (the bypass radiator) is fully openEnsure that the boiler's water pressure is between 1.0 and 1.5 barWait up to 10 minutes for the status code to clear automatically as it is often part of normal operation

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Related fault codes

S.20View →S.24View →S.28View →

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