BoilerFaultCodesTechnical description
Internal control box failure: check/replace the control box.
What causes this fault?
This fault occurs when the boiler's internal computer suffers a critical memory or communication error that prevents it from managing the gas valve and sensors. It is usually caused by electrical components on the circuit board wearing out over time or being damaged by a sudden power surge. Because the 'brain' can no longer guarantee the boiler is operating safely, the system shuts down entirely as a protective measure.
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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