High
36 on Grant Vortex Eco

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.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Vent B (in²)

From this model's manual
Verified against the Grant Vortex Eco installation & service manual, page 30.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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