Dryer would run but no heat

Mine is a 15 year old stacked washer-dryer unit. Once, with the help of this site, the problem was diagnosed and the part bought, the repair was almost completed. I had only to unplug the dryer; remove two screws to open the front panel, then to loosen one hex head screw to remove and replace the part and to plug it in. All done with a 6 in 1 screwdriver in less time than it took to remove the part from the blister pack. My dryer was probably easier than most to repair.