BoilerFaultCodes UNSTABLE FLAMES Emergency
Your boiler is struggling to keep its internal flame lit steadily, which means it cannot safely or reliably provide you with hot water or heating.
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) Water in gas line; II) Faulty flue
Typical repair cost £150-350 (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 UNSTABLE FLAMES — no call-out fees, no surprises.
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Chaffoteaux Britony II 50FF 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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