I've had a similar problem with my tumble dryer (not sure of the make and model, almost certainly different to yours!). I have a v. good shop near me who will give advice on this sort of thing, and they said it sounded like the thermostats had blown - they told me how to access them (covered by a metal cover secured by a couple of screws at the back of the machine) and what to look for (they were small round units, and the middle of each one depressed slightly when pressed, indicating they were dead). They sold me a pair of new thermostats (cost about 10-15 pounds) which I fitted and everything worked perfectly. One thing they did say is that you should not open the door whilst the dryer was running, as this greatly increases the risk of blowing the thermostats. I suggest you try to find a small elecrtical retailer who also sells parts and does repairs. Of course, if you live near them, I can recommend Automatica in Crayford, Kent.
Keith
November 2008