BoilerFaultCodesGrant 143 Fault Code
The Grant 143 fault code means: your boiler is struggling to get the right amount of air, which usually means the permanent ventilation opening in the room is obstructed or insufficient for the appliance to run safely.. It appears on 6 Grant models in our database.
Technical description: Vent A (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 143 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant 143 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