Emergency
A04 on Ferroli Energy Top B

Your boiler has detected an issue with the system that removes waste gases, so it has safely shut down to prevent the buildup of dangerous fumes.

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

Fume extraction duct safety device activation

From this model's manual
Verified against the Ferroli Energy Top B installation & service manual, page 38.
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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