BoilerFaultCodesTechnical description
System configuration: new BUS device. New ISM detected.
What causes this fault?
This fault occurs when the boiler's main control board detects a new electronic component or external wireless device trying to communicate with it. It acts as a security handshake, triggered because the system needs manual permission to integrate the new hardware and ensure it is compatible. The most common reason is that a new smart thermostat or internal wireless module has just been installed or replaced.
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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