Most probably a short circuit in the heater.
Heater is located at bottom of drum. If testing with a multimeter, disconnect the wiring and take a resistance reading across the terminals - should be around 20 ohms. If heater is blown (broken internal heater wire) it will give an infinite resistance. There should be no continuity between the either terminal and the metal sheath of the heater - if there is, there's an internal short circuit. When replacing heater, disconnect wiring, undo central mounting nut and prise it out of its rubber seal - may require some effort. Replace heater, use sealant when refitting rubber seal and ensure it is fully pushed into the recess in the backplate. 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.
Check out www.2ndwave.co.uk/manual.html
dannyboy, October 2008
