BoilerFaultCodesYour boiler has started an ignition process but the flame has gone out, meaning the system has shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: FLAME LOSS
What causes this fault?
This fault occurs when the boiler successfully lights but the internal sensors fail to detect the flame, causing the system to shut down for safety. The most common reasons are worn-out ignition parts that can no longer 'see' the fire, or an inconsistent gas supply that prevents the flame from staying lit. In some cases, a blocked flue or debris on the burner can also interfere with the combustion process.
This fault is more common in winter, as extremely cold temperatures can cause the gas meter regulator to freeze or 'lock up,' restricting the gas flow needed to maintain a steady flame.
DIY fix possible
Check that your gas stop tap is fully open and that you have credit on your gas meter.Check if other gas appliances in your home, such as a hob, are working correctly.Reset the boiler by turning the primary knob to the 'RESET' position and holding for five seconds.
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 F2 or Fn or Ln — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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