Heyya,

I have a GE Profile Side by Side ref, PSS25SS, with a heavy frost build up on the back of the freezer. When I thaw it out and start it up again, it is fine for a week or so and then stops working correctly again - it warms the freezer up to about 19 degrees and runs constantly. Could it be a heater bracket and assembly or the heater harness?

I would appreciate any thoughts on what part I should be trying to replace.

Thanks.

You need to check your defrost heater located under the freezer coils. Most likely it is burned out and needs replacing. There is also a thermistor that senses the temperature of the freezer coils. If it goes bad, the defrost heater will not come on. To test the thermistor you will, of course, need an ohm meter. There is a chart in the manual showing what the readings should be: https://dl.dropbox.com/u/8010163/GE_Profile_Side_by_Side_refrig.pdf
https://dl.dropbox.com/u/8010163/How%20to%20use%20Test%20Equipment%20Service%20Manu al.pdf
Do not try a repair with no meter. You can easily ruin something by replacing good parts.

Defrost heater tests fine with a multimeter. Is the next step to test the evaporator thermostat? I understand that the third possibility is the termistor, but I don't feel like I can check that myself. Does this model have a motherboard?

Thanks for all the help.

Of course you have to check the t-stat. You have to submerge the t-stat in ice and water in order to test it. It should be closed at 32°. In order to test thermistors you use temperature and the chart to get the right readings. I know if my niece can do it, you should be able to do it. Buy a volt/ohm multimeter and learn to use it. It's really easy.

Ended up cutting out the thermistor and in testing it with a digital multimeter, can't get any reading at all. Am I doing something wrong or is this a sign of a bad thermistor?

You have a bad thermistor unless your meter is bad. There is a chart in the manual that shows what it is supposed to read at certain temps. Chill it down and see what you read.

Chilled it in ice water for 15 minutes, and it had no reading. Let it warm up, still no reading on the multimeter. Multimeter tested the heater correctly, and shows continuity in other items, such as a nail - plus shows zero resistance when used against itself as a baseline.

I'm going to get a new thermistor and see what happens.

You are right to replace it. There are different thermistors in that refrigerator, so get the right one. The one you want probably detects the temperature when defrosting and terminates the defrost cycle when it gets 35-40°.