BoilerFaultCodesHeatline S.41 Fault Code
Also written as S41 — same fault.
The Heatline S.41 fault code means: your boiler has detected that the water pressure inside the system is too high, which can put unnecessary stress on the internal components.. It appears on 7 Heatline models in our database.
Technical description: High pressure value
DIY fix possible
Check that the filling loop valves (under the boiler) are tightly closed.Locate a radiator bleed valve and use a key to release water into a container until the pressure gauge returns to 1.5 bar.Restart the boiler to clear the code.
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Heatline models that show the S.41 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Heatline S.41 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.
- Heatline CaprizPlus 28 manual (PDF)
- Heatline CaprizPlus 24a manual (PDF)
- Heatline Compact 24 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026