BoilerFaultCodesYour boiler is struggling to keep a flame lit, which means the system has safely shut itself down to prevent a fault.
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's internal sensors lose track of the flame after it has already started. The most common reasons are a buildup of carbon on the ignition parts or a blockage in the condensate trap that causes water to back up into the heat exchanger. It can also be triggered by an unstable gas supply or a faulty gas valve failing to maintain a steady flow.
This fault is more common during freezing winter temperatures, as a frozen external condensate pipe can cause water to back up and extinguish the flame.
DIY fix possible
Check that your gas pre-payment meter (if you have one) has credit.Verify that other gas appliances, like a hob, are working correctly to rule out a gas supply issue.Restart the boiler by pressing the 'Reset' button on the display panel.
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 4.4 — 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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