Medium
S.54 on Vaillant Home Combi

Your boiler is temporarily paused because it has detected that the water inside your heating system isn't circulating correctly or the pressure is too low.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

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

What the manual says

Manufacturer manual

Waitingperiod:Lowwaterpressureinthecircuit(flow/returnspreadtoolarge)

From this model's manual
Verified against the Vaillant Home Combi installation & service manual, page 35.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check your boiler's pressure gauge to ensure it is between 1.0 and 1.5 barIf low, use the filling loop underneath the boiler to top up the pressureCheck all radiators to ensure they are fully bled and that their valves are open

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