There are many symptoms that can take you off track as to the real symptom. I was helping a friend troubleshoot his refrigerator. First, I have to describe that it is a double door 23-25 cu inch refer, with ice maker, water and ice dispenser. It was a Sears Kenmore Model Number 363.9534710.
The refrigerator was about 9 years plus old. It would Ice up after a few weeks. It appeared to be cooling well but I suspected that it was not performing regular defrosting
The refrigerator also had a torn seal in the base of the main food area on the door and my friend thought that might be causing the Freezer coils to completely ice up and stop cooling after a few weeks, depending on how many times they opened it.
I knew a good deal about appliance repair but I wanted to do some research prior to jumping in. To my surprise, at Appliance 411, I found an article that was by far the most comprehensive general refrigerator article I had read in a long time. http://www.appliance411.com/faq/howdefrostworks.shtml
My experience suspected the defrost timer being stuck or slow or both. If it stops it can the refer from ever defrosting then it will eventually ice up. The defrost cycle consists of glass and coiled heaters that heat up the coils in the Freezer section to keep it from icing up.
I pulled the Defrost Timer out which is located IN the main food area or the right compartment inside on top. It as a smaller defrost timer, unlike the older bulkier more unreliable ones of the past so I started to rule that out just as a hunch.
Then I turned to the Freezer section and removed the 4 cooling coil cover screws against the back of the freezer compartment, exposing the coils and the 2 defrost heaters that are setting at the top and the bottom of the cooling coils encased in metal protection.
When troubleshooting, I was taught was to always make visual inspections of parts and in general. Look for something burnt, broken, out of place, unsymmetrical.
I looked at the upper glass covered heating coils and it looked clean and ok, but the lower one was not the same and the glass was discolored, look burnt. If you know how to use a continuity tester to test for a complete circuit, you can test both tubes by unplugging the plug with the Blue Orange and pink wires. or remove each heater and test each one for very very low resistance, like under 5 ohms. You are looking for an open and any reading under 10 ohms will be ok.
Don’t forget the small button thermostat that controls the defrost coils from coming on and off. Nothing will work if that does not close and complete the connection to defrost. The way to test them is push the button into a glass of ice chips and wait 4-5 minutes. If it works it will turn on and complete the connection of the two wires Orange and Pink and you can pretty much rule out that.
So, in this case I unscrewed the lower heating element to get a better, more physical look at it. The coil was broken inside which make me 100% certain I found the issue.
The two coils and the thermostats come as a set and the part number is WR51X0372 replaced by new part number of WR51X443. They are $65 from sears parts distribution center and close to $100 anywhere else. Go here and get the model number on the lower right side of the right door, not on the door but facing you on the frame. http://www.searspartsdirect.com Search by model number and part number. You can find a local store or order it online.
Here are some helpful photos.
Tip – If your freezer seal is not closing well, depending on the age and flexibility, I have seen great success if you take a powerful hair dryer and heat the area that is pressed in and pull it out gently as you heat it. Let it cool and then close the door. It usually does the trick.
The Freezer door not closing properly and the ice dispenser round auto shut door not closing completely can produce similar symptoms of icing or frosting up.