Emergency
Air Flow Monitor Neon on Potterton Performa 24i HE

Your boiler is struggling to breathe because it cannot vent exhaust gases properly outside, so it has safely shut itself down to prevent a carbon monoxide hazard.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

The flue or flue terminal is blocked or obstructed in some way, or that there is an internal fault.

From this model's manual
Verified against the Potterton Boiler Performa 24i He installation & service manual.
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 emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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