BoilerFaultCodesGrant 41.5 Fault Code
Also written as 415 — same fault.
The Grant 41.5 fault code means: your boiler has detected an issue with the water pressure level, which has triggered a safety shutdown to prevent damage to the system.. It appears on 1 Grant model in our database.
Technical description: 41.5
DIY fix possible
Locate the external filling loop connected to your boiler pipesSlowly open the valves to allow water into the system until the pressure gauge reads between 1.0 and 1.5 barClose both valves tightly and reset the boiler
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Grant models that show the 41.5 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant 41.5 fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026