BoilerFaultCodesGrant 396 Fault Code
The Grant 396 fault code means: your boiler is struggling because the ventilation system providing fresh air to the unit is insufficient or blocked, preventing safe and efficient operation.. It appears on 6 Grant models in our database.
Technical description: Vent B (cm²)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Grant models that show the 396 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant 396 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