Emergency
YELLOW FLAMES SOOT FORMED on Chaffoteaux Corvec 28 OF BF

Your boiler is not burning fuel correctly, which is causing soot to build up and creating a serious risk of carbon monoxide production.

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

i) Heating body fms blocked ii) Primary air supply restricted iii) Wrong injector

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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