Thermostats blowing on Hotpoint TDC60?

Replaced thermostats about a week ago. Tumble action working but no heat. Asked an engineer who said that the machine should be left to run it's cycle or it should be switched to the fan symbol which would run the blowers until the elements cooled down. Apparently this will stop the heat conducting through the metal parts and blowing the thermostats. Replaced thermostats then it happened again within a week. Does any body have the answer please? Is there an exhaust thermostat? Is there a module which should control the heat output (only heats when the drum spins one way)? I have picked all this up from other forums. Also that if it is a faulty part Hotpoint will replace it free if machine is less than five years old - but they probably charge a fortune for the work? Please help if you can.