Your boiler's main internal computer has lost communication with one of its electronic parts, meaning it cannot operate until the connection is restored.

Module not detected.

What causes this fault?

This fault occurs when the boiler's central control board stops receiving signals from its internal electronic module. The most common cause is a loose connection in the wiring harness or a critical failure of the Printed Circuit Board (PCB) itself. If these sensors and modules cannot talk to each other, the boiler shuts down as a safety precaution.