Your boiler is failing to communicate with its primary control unit, meaning the system cannot start or maintain your heating and hot water.

Module not detected.

What causes this fault?

This fault occurs when the boiler's main control board loses the electronic 'handshake' with its internal software chip or plug-in components. It is usually caused by a loose connection during a service, a power surge that has glitched the electronics, or a component failure on the PCB itself. Essentially, the brain of the boiler can no longer see the vital parts it needs to operate safely.