BoilerFaultCodesGrant 198 Fault Code
The Grant 198 fault code means: your boiler is struggling because the ventilation supplying air to the room where it is installed has become blocked or is insufficient, preventing the boiler from breathing properly.. 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 198 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant 198 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