The fan might still be faulty, however there is probably a thermostatic switch somewhere, which "switches on the fan" when it reaches a certain high temprature. You can try and follow the wires from the back of the fan to the "switch". You can remove the switch and test it in a pot of boiling water on the bench or just replace it if its only a few quid. Be carefull with the hot water.
B
September 2008