Tip & How-To about Refrigerators

How to repair a defrost system.

Is there ice/frost build up at the rear inside of the freezer? (If not go to the evaporator fan). You are having a problem is with your defrost system.
This is going to be one of three problems with your refrigerator, First thing to do is remove shelf’s and panel in the back of the Freezer. You may see ice build up on the evaporator, don't worry get a hairdryer and melt the ice.
Next locate the wires for the defrost heater and using a multi-meter/ohms meter test the heater for continuity (it should read infinite) if the defrost heater is bad replace it.
This is what a typical GE defrost heater looks like:
 
If the heater is good test the defrost thermostat. This should normally be done when the evaporator is still covered with ice since it will only activate at 40f - 50f depending on the thermostat. When tested with the ohms meter at below 40f it will read infinite. It is normally clipped to the upper right of the evaporator and look something like this:

The next possible problem could be the defrost timer. If you have tested the heater and thermostat and they have tested good next find the defrost timer. If your refrigerator has a mechanical one it will either be located inside the control panel in the fridge or behind the panel below the doors. Once you have located it advance the dial until you hear a click. This will initiate the defrost cycle. If your heater begins to get hot this will tell you that your timer has stalled and needs to be replaced. A typical mechanical timer looks like this: If your refrigerator has a digital defrost timer you should locate the tech sheet. Normally you can find this behind the panel under the doors. It will tell you how to initiate a manual defrost cycle. As before if the heater gets hot you will have to replace the mother board normally located behind a panel at the rear of your refrigerator.
If your fridge is warm and there is no build up of frost/ice on the back panel inside the freezer then you problem is most likely going to be the evaporator fan. Have you heard the fan running in the past few hours? If you are not sure pull the panel out to where you can see fan and watch it over the space of an hour to see if it turns. If you don’t see it turning replace the motor.
This is what a typical evaporator fan looks like:Mike

Posted by on

Refrigerators Logo

Related Topics:

Related Questions:

1 Answer

kelvinator no frost


Please check if there is build up ice around evaporator fan.
Remove rear cover in the freezer and check defrost cycle

Aug 26, 2014 | Kelvinator Refrigerator Fridge Freezer...

1 Answer

I had water in bottom of kenmore fridge. This is now fixed but soon after I had frost building up on back wall of freezer.


you now have a defrost issue,remove rear panel inside freezer if the evaporator is covered with a heavy ice and frost build-up then either the defrost heater under the evaporator coil is open or the defrost thermostat on top of the coil is bad you need to check both for continuity or the defrost timer if equipped or the A.D.C. adaptive defrost control is bad and not supplying power to the defrost circuit

May 02, 2012 | Kenmore Top Freezer Refrigerator

1 Answer

fridge doesn't cool.


Hello, would you happen to have the make and model number of your refrigerator? In a refrigerator the freezer side of the refrigerator is the only side that produces the cold. If your refrigerator side is not cool but your freezer side is one of the first things that you would check would be to open the freezer door and look along the rear wall of the freezer to see if you notice any frost or ice build up on the rear wall. If you did this is termed as a defrost issue and message me back that you do have this situation and I will instruct you how to diagnose this to correct this situation. If you had no ice/frost build up on the rear wall you would next assure that the evaporator fan is blowing air inside of your freezer. If you felt no air blowing inside of the freezer you would then remove the rear wall on the inside rear of the freezer by unscrewing the 1/4" screws. This would give you access to the evaporator coil and above the coil would be the evaporator fan motor. I will await your reply to your finds as to if there is any ice/ frost and if the evaporator fan is blowing air inside of the freezer before further diagnosing.
Thank you
Rick

Oct 25, 2011 | Refrigerators

1 Answer

Kenmore Freezer 106.727581: The freezer ices up and the temp goes up to 34 degrees. If I manually defrost it, it goes to 5 below zero in about 6 hours. How can I determine which of the below need to be replaced; Timer-defrost defrost Bi-metal Heater Defrost Condenser fan


The refrigerator is supposed to self-defrost approximately four times in every 24 hour period. If one of the components in the self-defrosting system fails, the refrigerator continues to try to cool. Eventually, though, so much frost builds up on the evaporator coils that the circulating fan can't draw air over the coils. There may still be a small amount of cooling because the coils are icy, but with no air flow over the coils, cooling in the refrigerator compartment is quite limited. Poor cooling is often the result of a heavy frost build-up on the evaporator coils. You can't see these coils without removing a panel on the inside of your freezer. A sure sign that there is a build-up is the presence of any frost or ice build-up on the inside walls, floor, or ceiling of the freezer. Such a frost build-up usually indicates a problem in the self-defrosting system or damaged door gaskets.Here's an inexpensive, though inconvenient, way to determine if the problem is with the self-defrosting system. Remove all of the perishable food from the refrigerator and freezer, turn the thermostat in the refrigerator to Off, and leave the doors open for 24 to 48 hours. (Be sure to have several towels ready in case the melting frost and ice causes the drip pan to overflow). This allows the refrigerator to defrost "manually." When the frost and ice build-up has completely melted away, turn the thermostat back to a normal setting. If the refrigerator then cools properly, it indicates a problem with one of three components in the self-defrosting system: The defrost timer The defrost thermostat (also called the bi-metal switch) The defrost heater. To determine if the defrost heater is burned out, watch this part testing video

Aug 21, 2011 | Kenmore Freezers

1 Answer

I think my evaporator fan is out everything in fridge is warm to touch and ice is built up on freezer wall at rear of freezer and ice cubes will not freeze solid.also do not hear fan running any more


Hi there
I have found some stuff for you to read hope this helps you. Let me know how it goes.
Cooling is poor For an overall understanding of how refrigerators should work, read about refrigerators in the How Things Work section of our website. A refrigerator or freezer that is cooling, but cooling poorly, may have a problem in one of several areas: Evaporator coils Condenser Poor cooling is often the result of a heavy frost build-up on the evaporator coils or a condenser that is clogged with dust, lint, and dirt. Evaporator coils Poor cooling is often the result of a heavy frost build-up on the evaporator coils. You can't see these coils without removing a panel on the inside of your freezer. A sure sign that there is a build-up is the presence of any frost or ice build-up on the inside walls, floor, or ceiling of the freezer. Such a frost build-up usually indicates a problem in the self-defrosting system or damaged door gaskets. The refrigerator is supposed to self-defrost approximately four times in every 24 hour period. If one of the components in the self-defrosting system fails, the refrigerator continues to try to cool. Eventually, though, so much frost builds up on the evaporator coils that the circulating fan can't draw air over the coils. There may still be a small amount of cooling because the coils are icy, but with no air flow over the coils, cooling in the refrigerator compartment is quite limited. Here's an inexpensive, though inconvenient, way to determine if the problem is with the self-defrosting system. Remove all of the perishable food from the refrigerator and freezer, turn the thermostat in the refrigerator to Off, and leave the doors open for 24 to 48 hours. (Be sure to have several towels ready in case the melting frost and ice causes the drip pan to overflow). This allows the refrigerator to defrost "manually." When the frost and ice build-up has completely melted away, turn the thermostat back to a normal setting. If the refrigerator then cools properly, it indicates a problem with one of three components in the self-defrosting system: The defrost timer The defrost thermostat (also called the bi-metal switch) The defrost heater If it still does not cool properly, there may be a problem with the refrigerant level or the compressor. You may need to consult with a qualified appliance repair technician to further diagnose the problem
Thank you for writing to fix ya.
Best Regards Richard

Dec 27, 2009 | LG LRBN22514ST Bottom Freezer Refrigerator

Not finding what you are looking for?

923 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Refrigerators Experts

John Tripp
John Tripp

Level 3 Expert

4654 Answers

yadayada
yadayada

Level 3 Expert

76070 Answers

Brian Coughlan

Level 2 Expert

275 Answers

Are you a Refrigerator Expert? Answer questions, earn points and help others

Answer questions

Loading...