36 High

Grant 36 Fault Code

The Grant 36 fault code means: your boiler is struggling to breathe because the ventilation opening in the room where it is installed is too small or blocked, preventing the unit from getting enough air to operate safely.. It appears on 6 Grant models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Vent B (in²)
Typical repair cost £150-300 (including labour)

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 36 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Grant 36 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