BoilerFaultCodes 8.11 Emergency
Your boiler is burning gas incorrectly, which is creating dangerous soot and could lead to carbon monoxide leaking into your home.
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: Yellow Flames - Soot Formed
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 8.11 — no call-out fees, no surprises.
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Chaffoteaux Britony Duo 55 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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