BoilerFaultCodesHeatline S.41 Fault Code
Also written as S41 — same fault.
The Heatline S.41 fault code means: your boiler's internal water pressure is currently too high, which prevents it from operating safely to protect the system.. It appears on 2 Heatline models in our database.
Technical description: High pressure value
DIY fix possible
Locate a radiator in your home with a bleed valvePlace a cloth and container under the valveOpen the bleed valve slowly to release water until the boiler pressure gauge drops to the green zone (usually 1.5 bar)Close the valve tightly
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A cover plan would handle faults like S.41: no call-out fees, no surprise bills.
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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.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026