BoilerFaultCodesYour boiler is failing to detect a flame after it tries to ignite, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ionisation failure
What causes this fault?
This fault occurs when the boiler's internal computer cannot confirm that a flame has successfully lit inside the combustion chamber. The most common reasons are a worn-out sensor that can no longer 'see' the flame, a buildup of carbon on the electrodes, or a lack of gas reaching the burner.
This issue is slightly more frequent during the first cold snap of winter, as gas valves can occasionally stick after being inactive throughout the summer months.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like E5 — no call-out fees, no surprises.
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Worcester Bosch WR325 RSF 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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