Does your dryer have a thermal cut out switch on the back?. It'll be a red button. Press it. If it goes click, it means the temperature got too hot in the dryer and tripped the switch and turned off the heat. If not, you'll need to open the top of the dryer. Looking from the front, to the left at the back you should see where all the wires come in from the ground, power, thermal cut out, element, thermostat, etc. There are 6 I think. Get a multimeter with a circuit test on it. Put the black lead on the ground lead which should be the far left one. Then check the 3rd or 4th line from the left. One is the element, one is the thermostat and there will be one there from the cut out switch. If any of these don't make a circuit, then that will be the faulty part. On mine it was the thermostat which fried before the thermal cut out turned it off. I personally got an engineer out to diagnose the fault first which was free. Then I bought the part myself and replaced it. If you buy direct from Bosch spares make sure you buy the right part as they don't do returns unless you're an engineer.
Lee, October 2006