BoilerFaultCodesTechnical description
check the wiring harness
What causes this fault?
This fault occurs when the boiler's internal computer chips lose the ability to talk to each other through the electrical circuitry. It is usually caused by a loose connection in the internal wiring or a mechanical failure within the main control board that prevents signals from being sent correctly. Because the boiler cannot verify that all systems are safe, it shuts down 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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