BoilerFaultCodesYour boiler has failed to light because it either cannot get enough gas or it cannot detect the flame it has sparked.
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 fails to establish or maintain a stable flame. The most common reasons are a temporary interruption in the gas supply, a blocked burner, or an ignition probe that has become worn and can no longer sense the heat from the flame.
This fault is more frequent during freezing winter spells, as the boiler's external condensate pipe can freeze and back up, preventing the unit from lighting successfully.
DIY fix possible
Check that your gas stopcock is fully open and your gas meter has credit.Try turning on another gas appliance, like a hob, to see if the gas supply is active.Press the 'Reset' button on the front of the boiler for five seconds.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E133 — no call-out fees, no surprises.
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Potterton Gold HE 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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