I have an Kenmore Gas/propane dryer that stop heating up the other day. I ran on both the sensor setting and timed settings for extended periods. Both settings would not dry the clothes. I put in a call to have it looked at and the repairs are supposed to happened today. This morning my wife decides to run it just to double check it again, and it started heating again. Any clue as to what causing it to not work one day and then start working again? Any help to eliminate a house call is appreciated. Thanks