BoilerFaultCodesYour boiler has failed to light the gas after several attempts, which means your heating and hot water will not work until the system is reset.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Refer to fault finding section on Page 30 (displayed when control fails to detect flame after ignition attempts).
What causes this fault?
This fault occurs when the boiler tries to start but can't detect a flame, causing the system to shut down for safety. It is usually caused by worn-out ignition parts that can't create a spark or a gas valve that isn't opening correctly to let fuel into the burner.
This issue often surfaces during the first cold snap of autumn when the boiler is pushed to work harder after being idle all summer.
DIY fix possible
Check if your gas supply is active by testing another gas appliance like a hobEnsure your gas meter has credit if you use a prepay meterPress and hold the reset button for 5 seconds to clear the fault
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 A01 — no call-out fees, no surprises.
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Potterton Envoy 30 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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