BoilerFaultCodesYour boiler has failed to light because it either cannot get enough gas or cannot detect a flame once ignited.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Interruption Of Gas Supply or Flame Failure
What causes this fault?
This fault occurs when the boiler attempts to ignite but cannot establish or maintain a steady flame. The most common reasons include a lack of gas reaching the burner, a faulty ignition spark, or a sensor that is too dirty to detect that the flame has successfully lit.
This fault is more frequent during extreme cold spells because the external condensate pipe can freeze, causing a backup that prevents the boiler from igniting.
DIY fix possible
Check that your gas emergency control valve is open and any prepay gas meter has credit.If it is freezing outside, check that the white plastic condensate pipe leading outdoors is not frozen and blocked.Hold the 'Reset' button for five seconds to attempt to restart the boiler.
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A boiler cover plan would cover faults like E133 — no call-out fees, no surprises.
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