Think some of you may find this interesting.
A couple of weeks ago our dishwasher packed up, not to worried as I pay a kitchen appliance ins, engineer (well possibly not) arrived, didnt test anything, just said it could be: heater, thermostat or main pcb control board, three days later arrived with all the parts, and proceeded to fit all three, cost of main pcb £240. heater £65 T/stat £20, now of course it doesn't cost me anything so why worry. My point is does no one have to train to have the required diagnostic skills, that we used to have it just wasn't acceptable to keep changing bits, till you found the problem.