BoilerFaultCodesYour boiler is struggling to light and stay on, which can sometimes be caused by trapped air in your heating system preventing the water from flowing correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ignition failure – try bleeding your radiators
What causes this fault?
This fault occurs when the boiler tries to light the flame but fails to detect one, causing the system to shut down for safety. The most common reason is that the spark isn't strong enough to ignite the gas, or the sensor that monitors the flame has become dirty or worn out. It can also be triggered if air is trapped in the system, which disturbs the internal pressure and prevents the boiler from operating correctly.
This fault often appears after the summer break when the boiler is switched back on for the first time or after the system has been drained for radiator maintenance.
DIY fix possible
Turn off the boiler and wait for the radiators to cool downUse a radiator key to bleed any air from all radiators in the houseCheck the boiler pressure gauge and top it up to 1.5 bar if it has droppedPress the 'Reset' button on the boiler control panel
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A boiler cover plan would cover faults like E4 — no call-out fees, no surprises.
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Baxi Avanta 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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