Your boiler's internal computer is reporting an error with its software version or internal memory communication.

Control device version: Software version of the control unit.

What causes this fault?

This fault occurs when the boiler's main control board loses communication with its internal memory or cannot verify its own software. It is essentially a digital handshake failure between the central processing unit and the specific data chip that tells the boiler how to operate safely. The most common reason is an electronic component failure within the printed circuit board or a corruption of the software on the code plug.