BoilerFaultCodes Main burner will not light or lights at low flame (12) High
Your boiler is struggling to ignite or produce enough heat because the internal pipes that transfer warmth are likely clogged with debris.
Call an engineer soon
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Heat exchanger blocked.
Typical repair cost £250-500 (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
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Chaffoteaux Flexiflame 140 is discontinued — time for a new one?
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