Firstly, the Ice Door had a kink in the edge, which caused it to stay open and create lots of frost on the coils. $5.00 part, highly recommend it. (By the way, the new door was little too big and it too stay propped open and left a gap so I had to trim the top edge of the rubber with scissors to get it to fully close.) Secondly, there are two heaters for the defrost cycle, one that goes around the coils and another attached to a collector pan beneath the coils. When the cycle hits, those heaters come on and turn the ice to water. The water in the pan was supposed to then drain out the hose. But the hose in my unit kept getting clogged. At first I cleared out a bunch of gunk. But then after going through this a few times I realized it was getting clogged with ice. Turns out that the defrost heater around the coils worked fine but the one attached to the collector pan was failing. Ice would melt off of the coils and drip into the pan where it would remain frozen. Ice got so thick that it blocked the drain hose. The water would pour over the edge of the pan and down into the freezer compartment. Granted, I had excess frost build up, but without the pan heater it just overflowed instead of going out the drain. So, from inside the freezer I had to remove all the metal panels, break apart the styrofoam up inside the freezer (and beneath the coil), remove the old pan and put in a new one. The replacement heater pan came with styrofoam, but I had to trim it here and there to get it to fit. I hope you found this note helpful. I rated the repair a 4 not because the actual process was difficult but the diagnosis stumped me for so long. Had to do it over and over several times before I figured it out. Most DIYers should be able to complete the replacement in less than two hours.