My tcem80c6g condensor tumble dryer keeps stopping and starting put cloths in set timer for say 60mins it lasts for 10 mins then stops for 20 mins restarts for 5 mins then stops again I have gave it a real good clean out . Someone said to replace thermostats at rear where heater is I replaced the two of these heat was never an issue it’s fine it’s the stopping and starting that’s the problem a 60 min cycle now takes 4 hours .any help would be gratefully many thanks