Creda plan Integrated Dishwasher fault

Hi our literature describes the dishwasher as a CredaPlan so I have taken a (probably poor) guess at the most similar model. The machine is built in and 10+ years old, and non electronic.
It has a 2400W heater & 480W motor

The fault is that the unit is dead with the door closed, but fires up with the door open.

The machine is built in and a big hastle to replace.

Any ideas where to look first?


thanks in advance

Geoff