BoilerFaultCodesTechnical description
Ionisation oscillator test
What causes this fault?
This fault occurs when the boiler's internal computer fails a critical self-test regarding the flame detection circuitry. It is usually caused by a hardware failure within the main control board or a communication error in the internal wiring, meaning the boiler can no longer safely monitor the burner. Because the system cannot guarantee it is detecting the flame correctly, it shuts down as a safety precaution.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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