Your boiler's internal computer parts are having trouble communicating with each other, causing the system to shut down for safety.

Software incompatibility. Incorrect user interface or main board. Incorrect product code

What causes this fault?

This fault occurs when the boiler's internal control boards are unable to 'talk' to each other, often after a component has been replaced or due to a memory error. It physically happens because the software version on the main circuit board does not match the version on the display panel, leading the boiler to shut down as a safety precaution. The system effectively becomes confused and stops working because it cannot verify that the internal instructions are consistent across all parts.