The refrigerator was warm and the freezer was cold. We kept having to manually defrost the freezer because it was not defrosting itself. We first checked the freezer heating element for continuity with a multimeter and found that it did have continuity. Next, we removed the defrost thermostat and placed it in ice water and checked it for continuity with the multimeter. It did not have continuity so we ordered a new defrost thermostat and replaced it. Everything is working as it should now.