Model Number: 253.60082411
Brand: Sears Kenmore
Age: 1-5 years

I have a Kenmore 253.60082411 refrigerator/freezer. I am having the following problem with this unit. Recently, I noticed frost appearing on the inside of the freezer, freezer burn on some food items and the refrigerator not nearly cold enough. The freezer was very cold. I put my hand in the back and couldn't feel much cold air coming through the vents. I emptied both the freezer and refrigerator, removed the back panel of the freezer and noticed that the hole between the refrigerator and freezer was clogged with ice. I defrosted the unit, removed the ice and everything was fine for a few days. Now, I notice the refrigerator getting warm again and frost appearing in the freezer. The coils on the inside of the freezer have a lot of white frost on them and the hole is clogged again.

This unit has some self-test ability. I was able to trigger a defrost cycle by pressing the door button 5 times. This caused a lot of water to dump into the fresh compartment.

What is likely the problem and what would be the proper way to confirm the part that is defective?