why does my dishwasher throw the cut out?

The circuit breaker trip will be because of an over current fault or more probably because of a short to earth.

You do not say if this is an instant fault as soon as power is applied - or as soon as a wash programme is started or at a certain later point during the washing cycle.

If asked to guess I would focus on the heating element.

But that's just a guess...
February 2015