Water stopped coming out of door and lines in back of fridge along with all the contents of the lower drawer were completely frozen. The next day the freezer would not get cold. I removed the back of the freezer and the evaporator was a solid block of ice. It defrosted and all was well for about a month. Same thing happened again but this time it is accompanied by a chemical smell. I tested the defrost heater with my DVOM and it was fine 26ohms. I removed it anyways and both ends smelled like the smell we were getting. I am going to replace it but I don't think that it is the origin of the problem. Possible defrost thermostat??? Any help would be appreciated.