BoilerFaultCodes Frequent sooting of heat exchanger and burners Emergency
Your boiler is struggling to breathe properly, causing dirty build-up inside its internal parts that can lead to dangerous fumes.
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: 1. Linting. 2. Insufficient combustion air to room or compartment. 3. Heat exchanger fins blocked. 4. Restriction in flue. 5. Wrong injectors fitted.
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 Frequent sooting of heat exchanger and burners — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Chaffoteaux Flexiflame 140 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.
Affiliate links — we may earn a commission at no extra cost to you.