Emergency
Air Flow Monitor on Potterton Performa 24i HE

Your boiler is struggling to breathe because the flue vent outside is blocked or the internal fan isn't pushing air correctly.

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

Flue or flue terminal is blocked or obstructed, or an internal fault

From this model's manual
Verified against the Potterton/Potterton Performa 24 Eco 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.

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like Air Flow Monitor: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

E119View →E160View →

All 18 fault codes on the Performa 24i HE

Seeing a different code? Every code this model can display, in one place.

67891011242526272829Flame FailurePump Fault or Low PressureSafety ThermostatSensor FaultSystem Pressure (3 bar or greater)

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →