Mailbag: Diagnosing Refrigerator Defrosting Problems

“There are some who call me….Tim” wrote:

Konichiwa Appliance Samurai,
My freezer ices over. So I figure it’s something related to the defrost system that’s not working, but how do you know if it’s the timer, heater, or thermostat? I manually defrosted and it took a few months to freeze up again. Is this worth my time to try to fix myself with a $20-50 part, or should I just bite the cheap-ass bullet and call a repair guy to fix my GE Model TFX20JASM WH icy freezer? I’m not the handiest girl, but I do own a drill.
Thanks for your help.

The above message was sent when you were offline, via your LivePerson site.

Message sent from IP:

Now why would a drill-totin’ gal even dream of calling a repair guy when she’s found Samurai Appliance Repair Man? Come with me now on journey through your refrigerator’s defrost system.

For your refrigerator with a defrost system failure, you have correctly reduced the problem to one of three components: defrost timer, defrost thermostat (also called a defrost terminator), or the defrost heaters. Now, we could get all technical talking about esoteric gobbledy-gook like measuring current, voltage and resistance at various points but the Samurai is gonna show you a low-tech way to diagnose these no-defrost problems.

refrigerator defrost timerrefrigerator defrost timerFirst, let’s turn our Vulcan squinties to the defrost timer. On your fridge, the timer is item #257 in the fresh food compartment but can be located in different places on different refrigerators. Whatever you do, unplug the refrigerator before you go rootin’ around for the timer.

The topside of the defrost timer is shown to the left, and the bottomside is shown to the right. Now, the reason I’m showing the seedy underbelly of this beast is because there’s a knob that I want you to turn. Dig into your purse and pull out quarter to turn the knob with–New Hampshire commemorative quarters work the best. Turn the knob slowly clockwise until you hear a big click. This means the defrost timer is now in defrost mode.

defrost heater and terminator kit for ge-built refrigeratorsNow pull your head outta the refrigerator and plug it back in. The light should come on, but you should not hear any motors running. Open the freezer and wait a few minutes. If the heaters and terminator are working properly, you may hear sizzling or even see an orange glow. Listen and look carefully. The other thing to look for is a steady trickle of water dripping into the condensate pan underneath the refrigerator. Give it a good five minutes. If it looks like the defrosting system is doing its thang, then the defrost timer was stuck in run mode–replace it. Otherwise, if nothing seems to be happening, then you can conclude that the problem is either the defrost heaters or the defrost terminator. How do you tell which one is bad? You don’t care–replace ’em both! Yep, the glass rod defrost heaters are usually the problem in this case but the terminator is so cheap that it’s not worth quibbling about–replace it, too. In fact, you can buy the defrost heaters and terminator as a single kit, shown here to the right.

Now, this bidness of replacing the defrost heaters and the defrost terminator at the same time is only true for refrigerators with glass rod defrost heaters. Some refrigerators, like Whirlpool-built refrigerators, use calrod defrost heaters instead of glass rod. Calrod is the type of material that electric range elements use in the oven or stove top. Calrod defrost heaters rarely fail and to fix defrost system problems on these refrigerators, replace both the defrost terminator and the defrost timer–these parts are inexpensive and prone to failure.

Still confoosed, grasshopper? Check out this interactive diagram of refrigerator guts. Go git ’em.

To learn more about your refrigerator, or to order parts, click here.


One thought on “Mailbag: Diagnosing Refrigerator Defrosting Problems

  1. behy123

    I have a side by side Amana frig that I got about ten years ago, about 6 months ago when it was getting cleaned up water got in the Defrost control board black box, and the board got zapped, so the frig did not turn on,
    A Tech guy looked at it and said that the board needed to be replaced, so I did change the board with a new one fro m a supplier, and still defrost cycle does not get in the loop, so every couple of weeks I have to defrost it manually.
    Another Tech looked at it and said the Heating Element is not functional, so I got a different one, and defrost cycle does not kick in still,(it is a 450Watts/110V, I had the only choice of 1000Watts/220V, because of the geographical location I am in, it is almost equivalent of 450W/110V.)
    Another Tech looked at it and said the Thermo-Disk is weak and can not pass enough current, so I replaced it, ML45 module, and defrost cycle does not kick in still.
    So I started to listen to the sounds of Off-On and defrost cycle and noticed that when the Element is trying to kick in, it sounds like it is trying to bring it on line, but after 2 or 3 seconds, a relay or a fuse or something trips out and drops the Element.
    So, I tried to put a relay to be energized by the Thermo-disk and power the Element from a different power source, but the Freezer fan does not come online.
    A tech suggested getting a mechanical timer, it is a two cycle operation for 6 hours cooling and 21 min defrosting, But I am reluctant to do that.
    Any idea to how to resolve this by staying with the actual components is appreciated.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.