Medium
S.53 on Vaillant aquaPLUS

Your boiler has temporarily paused because it cannot sense enough water flow to operate 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

Delay mode due to lack of water in system (~2,5 mins.)

DIY fix possible

Check the pressure gauge on the front of the boilerIf the pressure is below 1.5 bar, use the filling loop handles underneath the boiler to top it upEnsure all radiator valves are open to allow water to circulate freely

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Related fault codes

F.22View →F.24View →S.54View →

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