BoilerFaultCodesVaillant S.92 Fault Code
Also written as S92 — same fault.
The Vaillant S.92 fault code means: your boiler is currently running a routine internal check to ensure there is enough water flowing through the system to operate safely.. It appears on 5 Vaillant models in our database.
Technical description: Water circulation volume self-test. The self-test for the water circulation volume is activated.
What causes the Vaillant S.92 fault?
This status code appears when the boiler is performing a routine check to ensure the internal pump is moving water through the heat exchanger correctly. It is a protective measure to ensure the system doesn't overheat before the burner fires up fully. This is usually part of the boiler's normal start-up cycle rather than a component failure.
DIY fix possible
Wait for 5 to 10 minutes as this is often a temporary status code and not a permanent fault.Check that your radiator valves are open to allow water to circulate properly.Ensure the boiler pressure is in the green zone, typically between 1.0 and 1.5 bar.
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Vaillant models that show the S.92 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant S.92 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
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Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026