Medium
S.54 on Vaillant aquaPLUS

Your boiler has paused briefly because the water inside is heating up too quickly, which usually means the water isn't flowing through the system as fast as it should.

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

Delay mode due to flow temperature gradient too steep (approx 10 mins.)

DIY fix possible

Check that all radiator valves are fully openEnsure the boiler pressure is between 1.0 and 1.5 bar on the gaugeCheck for any strange noises that might suggest air is trapped in the pump or radiators

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Related fault codes

F.24View →F.22View →S.53View →

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