Some weeks ago my tumble dryer smelled of burning and stopped altogether. The heater element had broken so i replaced the heater element and the two thermostats.
Now it starts fine and works for about 3 to 4 minutes then completely stops. It takes about half an hour or so unplugged before it can start again. It sounds like it is overheating and tripping out.
There is a third stat above the door which can also fail, but you may well have a fault in the notorious Dryness module. As far as I know there is no one that repairs these modules & they are pretty expensive to replace £100 – £120 depending on where you buy.