BoilerFaultCodesTechnical description
no communication to mainboard | connection error display mainboard
What causes this fault?
This fault occurs when the communication link between the boiler's control interface and its main brain is broken, preventing any commands from being processed. The most common reason is a loose or damaged internal wiring connection, though it can also be triggered by a power surge that has damaged the delicate circuitry on one of the electronic boards. Without this digital conversation, the boiler cannot safely ignite or operate.
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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