BoilerFaultCodesYour boiler has failed to light because it is not receiving enough gas or cannot detect the flame used to heat your water.
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 error
What causes this fault?
This fault occurs when your boiler tries to light itself several times but fails to establish or maintain a steady flame. The most common reason is a shortage of gas reaching the burner, often caused by an external supply issue or a blockage in the internal components. It can also happen if the sensor that monitors the flame is dirty or damaged, preventing the boiler from knowing it has successfully fired up.
This fault is much more common during freezing winter temperatures, as the external condensate pipe can freeze and back up, preventing the boiler from lighting.
DIY fix possible
Check if other gas appliances, like a cooker hob, are working to confirm your gas supply is active.If you have a prepayment meter, check that you have enough credit.Locate the white pipe beneath the boiler and ensure it hasn't frozen if the weather is very cold.Press the 'Reset' button for five seconds to see if the boiler restarts.
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A boiler cover plan would cover faults like E133 — 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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