BoilerFaultCodesTechnical description
BUS communication fault: Incorrect BUS subscriber connected.
What causes this fault?
This fault occurs when the boiler's main computer chip loses its ability to 'speak' to your wall thermostat or smart controller. It is usually caused by a loose connection in the wiring, a faulty circuit board, or an incompatible smart hub being plugged into the system. Essentially, the boiler has received a signal it doesn't understand and 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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