Your boiler's control panel has lost communication with the main computer, meaning you cannot adjust settings or operate the unit.

Local user interface fault

What causes this fault?

This fault occurs when the display panel on the front of your boiler can no longer 'talk' to the main internal computer. The most common reason is a loose or damaged connection cable inside the unit, or a components failure on one of the electronic circuit boards. Because the brain of the boiler cannot receive commands from the buttons, the system shuts down as a safety precaution.