Low
d.24 on Vaillant Home System

Your boiler is checking whether there is enough water pressure to run safely, but it hasn't yet confirmed if the pressure switch is active.

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

Status of the pressure monitor: off=Not switched, on=Switched

DIY fix possible

Check the water pressure gauge on the boiler front or digital displayIf the pressure is below 1.0 bar, use the filling loop to top it up to 1.5 barEnsure all radiator valves are open and there are no visible leaks

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Related fault codes

F.22View →F.24View →d.05View →

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