BoilerFaultCodesYour boiler has detected an internal error while trying to check if the flame is burning safely, causing the system 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: Internal fault when testing the ionisation signal
What causes this fault?
This fault occurs when the boiler's internal computer fails to properly monitor the electrical signal produced by the flame. The most common reason is a build-up of carbon on the sensing probe or a loose connection in the wiring that prevents the system from confirming the boiler is burning gas safely. In some cases, it can also be triggered by a glitch in the main circuit board itself.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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