BoilerFaultCodesYour boiler has tried to ignite but cannot detect a flame, which means it has stopped working to prevent a safety issue.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame not detected.
What causes this fault?
This fault occurs when the boiler attempts to light several times but the internal sensor cannot confirm that a stable flame has been established. The most common reasons include a lack of gas reaching the unit, worn-out ignition parts that fail to create a spark, or a build-up of carbon on the sensing probe. In many cases, it is simply caused by the burner becoming dirty or a blockage in the system that carries waste gases away.
This fault is more common in winter, as frozen condensate pipes are a leading cause of the boiler failing to ignite.
DIY fix possible
Check that your gas pre-payment meter (if you have one) has credit.Verify that other gas appliances, like a cooker, are receiving gas.Press and hold the 'Reset' button for five seconds until the display clears.If it is freezing outside, check if the white plastic condensate pipe is frozen and gently thaw it with warm water.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like EA — no call-out fees, no surprises.
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Worcester Bosch Greenstar 25i (ZWB 7-25) 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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