what instrument are you using to test the machine?low insulation is the easiest fault to find with a megger,component changing is a very expensive way to test a machine,as you have found out,
you need to test it properly,first remove the plug from the socket,check the cable itself back to the machine,check the capacitor,remove wires of each water valve,take note where they go,test them with megger.thats one clip from the megger to earth the other on each side of the valve in turn,test the motor,remove the plug from motor,check from each terminal to earth,remove all leads from heater,do same as you have done with motor,check door lock ,the megger should be set on 500 volts,be carful with the megger do not touch the crocodile clips when you press the button,,the power goes to door switch,then to the timer then to the control module then to varius components
mm, May 2013