Medium
S.59 on Vaillant ecoTEC exclusive

Your boiler is temporarily pausing because it cannot detect enough water flowing through the system to heat it safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Waiting time: Water circulation vol. (Minimum circulation water volume)

DIY fix possible

Check that all radiator valves throughout your home are fully openEnsure your system pressure is at the correct level, typically between 1.0 and 1.5 barCheck for any blockages in your external magnetic system filter if one is fitted

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Related fault codes

F.22View →F.24View →

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