Your boiler's internal computer has lost contact with its control panel or external sensors, meaning it cannot receive the instructions it needs to work.

Break in communication

What causes this fault?

This fault occurs when the boiler's main control board can no longer 'talk' to the display screen or external controls. The most common reason is a loose connection in the internal wiring, though it can also be caused by moisture damage or a component failure on one of the electronic circuit boards.