BoilerFaultCodes YELLOW FLAMES SOOT FORMED Emergency
Your boiler is not burning fuel correctly, which is causing soot buildup and indicates a significant safety risk from potentially harmful gases.
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 fins blocked, ii) Primary air supply restricted, iii) Wrong injectors
Typical repair cost £150-300 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like YELLOW FLAMES SOOT FORMED — no call-out fees, no surprises.
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Chaffoteaux Britony II 30FF is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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