It might be that a heater element has broken. The heater is made up of three elements which are basically wire coiled around a mica board or similar - they are surprisingly fragile. If one element has deteriorated and broken, it could sag down and touch one of the others causing the fuse to trip? I only noticed this with mine when it wasn't getting hot and I moved it out from under the worktop - the movement must have made two of the elements touch which flipped our trip switch. Hope this helps.
Robert, December 2008
