The sensor doesn’t work on our unit.   I threw our first load of towels in on the towel setting at 9pm and went to bed.  My husband opened the laundry room fort at 7:30 am.  The washer/dryer combo was still drying.  The room was very hot and the towels had been dry, I’m sure, for hours.  This was on a Saturday.  2 repairmen came on Friday.  They took it apart and cleaned it, didn’t replace the sensor.  We haven’t heard back from them yet. 
I’ve been letting all loads run for 3-4 hours.  If it doesn’t stop drying by then I open the door and everything is dry.  I let the last load of towels run for 4 1/2 hours.  It didn’t quit, but was very dry.  I don’t like our clothes getting over dry.  I don’t feel safe leaving the dryer unattended.  I would not recommend purchasing.