I finally received the control board for my water heater. Upon reading the instruction manual I found the following note:
"When replacing the control board the size of the container of the water heater and the integrated sensor offset eventually needs to be adapted. For this procedure you need the customer service plug."
From reading other material I know that the integrated sensor is a temperature sensor.
I already contacted the customer service, which states that they do not provide support for repair parts. Because I lack the customer service plug I wanted to ask what the worst is that can happen if no adjustments of container size and/or integrated sensor offset are made.
AEG DEM 80 Comfort EL Variowall