Emergency
A03 on Ferroli Econcept 100

Your boiler has detected an issue with its exhaust system, meaning it cannot safely clear waste gases and has shut down to prevent a 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.

Technical description

Flue safety device intervention. Flue partially blocked or insufficient

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 →

Related fault codes

A04View →F05View →

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 →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →