Your boiler’s internal computer has encountered a software or hardware error and can no longer communicate with the rest of the system.

System fault boiler electronics / basic controller

What causes this fault?

This fault occurs when the boiler's main control board experiences a critical internal communication failure, essentially meaning the 'brain' of the unit has become unresponsive. The most common reason is an electrical component failure on the printed circuit board or a loose connection within the internal wiring harness that prevents data from traveling between the sensors and the controller.