Closely inspect the entire wiring loom and circuit boards, looking particularily closely at areas where the wiring touches the machine frame. Your'e looking for any signs of wear or fraying which would allow the bare wire to contact the frame.
If this doesnt solve the problem, disconnect various components in turn before powering up. When you come to the point where the power breaker doesnt trip out you have the faulty component. Most likely culprits - heater or motor.
Repair and service your own washing machine. Go to www.2ndwave.co.uk/manual.html
dannyboy, November 2008