Medium
S.54 on Vaillant Atmomax

Your boiler has temporarily paused its heating process because it has detected a sudden rise in temperature and needs time to cool down before restarting.

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

Boiler is in waiting period of operation, blocking function as a result

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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 that all radiator valves are fully open to allow water to flow.Ensure the boiler pressure gauge is between 1.0 and 1.5 bar; top up if it is too low.Check for any air trapped in the system and bleed your radiators if necessary.

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