[tmeyer01]

I have a Kenmore side by side model 596.51672100 that has a condenser that keeps frosting up. I notice it each time the refrigerator fails to cool and then I see frost covering the back panel in the freezer. It used to do it every few months but now it's every few weeks. I have to remove the back panel inside the freezer and thaw out the entire thing. It becomes almost one solid block of ice from wires all the way down to the drip pan. I know there is something that make is "frost free" and assume that is what is not working. It's not warming it up to keep the frost off anymore. Can someone tell me what part I need and where it needs to go to get this fixed? The unit is only about 5 years old so I don't really want to replace it yet.
Thanks,

[Perito]

There is a defrost timer in frost-free refrigerators. I would check that first.

KENMORE | Model #59651672100 | 26' SIDE-BY-SIDE REFRIGERATOR | SearsPartsDirect.com

Possibly this one:

Defrost Timer

[tmeyer01]

I can not find anything like that on my refrigerator. What I do have is a adaptive defrost control board (a circuit board) inside the control box in the fridge with the temperature controls. I have attached a photo of the board. Is this what I need to replace to take care of my frosting issues?

Thanks,

[hvac1000]

You have the new style defrost control setup. I would test the defrost heater and the defrost bi-metal/defrost termination thermostat first since they are usually cheaper to replace that the control in the picture. I also believe that system has sensors so without a service manual you will not be able to test those items. The newer units are a pain in the A$$ to work on.

NOTE heater and bimetal if so equipped will be located in the freezer side behind the rear panel usually.

[tmeyer01]

I have the heating coil or evaporator at the bottom of the full freezer evaporator and I have a thermostat kit in the wiring at the top of the evaporator. Those are the only other two heating elements I can find.

I should test the thermostat first? Any idea how?

Thanks,

[hvac1000]

You need a special tool to test that board. The heater you want to test is the defrost heater located in the freezer compartment.

[tmeyer01]

I am referring to the components that are in the freezer compartment. I have a heating evaporator and a thermostat. Should there be something called a defrost heater in that compartment as well that I am not seeing?

[tmeyer01]

Here is a pic of what I'm looking at in the freezer area.

[hvac1000]

Round item clipped on line left side top is defrost termination thermostat. The temperatures of operation vary with the models of unit installed in.

Defrost heater located at end of black wires running down evaporator on the left side. Heater probably at or near bottom of evaporator.

Naturally make sure the little fan at the top operates during cooling only.

[tmeyer01]

Ok, I guess I was calling the defrost heater the heater evaporator since it has a hose similar to the evaporator. Is there a way to test the defrost heater or the defrost thermostat or should I replace one and hope for the best? If so, which one is most likely the culprit of the frosting?
Thanks again,

[hvac1000]

The heater should get hot with the application of 120 volts directly to the heater terminals (no other wiring attached). The defrost bi-metal thermostat will be very difficult to test without the proper tools since it is exact temperature test dependent.

[tmeyer01]

So just to clarify. I run 120 volts (or 110 from outlet?) directly to the black wires on the heater and see if it heats up? If so, it works. If not, it doesn't.

[hvac1000]

Yes that will work but with a word of caution. Insulate the wire attachments well since if the hot leg touches the evaporator coil it could short out causing a immediate loss of refrigerant. This will really get your attention since the refrigerant is under pressure. Good luck. PS you just need to see if it gets warm and it does not need to be hooked up a long time or the element will glow and that is not necessary

[tmeyer01]

I hooked it up and it certainly got hot so I'm good on that part. Would you suggest I replace the thermostat then and see if that does the job since that is too difficult to test anyway?

Thanks,

[hvac1000]

It is a bi-metal thermostat/defrost termination thermostat that is located in the compartment with the heater. Yes usually that part is not to expensive. Make sure to get the exact replacement!!

[tddougla]

Hope you don't mind, however I'm having a similar issue with the identical side-by-side. Clogs up behind the freezer back-panel above the circulation fan all the way up through to the upper refrigerator supply pass--thru. Have to chip out the pass-thru and behind the panel. Thought this was because the kids weren't closing the refrigerator door all of the way (possible door gasket), wondered if this would be mor indicative of the thermostat or heater issue you have been describing. Have already had to replace the compresser on this thing, don't want it to be too much more of a money pit.

[hvac1000]

Any signs of heavy frost or air restriction caused by frost in the freezer compartment usually indicates a defective timmer,defrost termination thermostat or the heater itself. Without being there it is impossible to tell in your case which part is defective OR if it has a plugged drain line.

[tmeyer01]

I tested the defrost heater and it worked so I replaced the defrost termination thermostat (got one for $27 and it's just a couple wires) and everything seems to be working great for my problem. Thanks hvac1000.

[hvac1000]

No problem. Glad you got it going.

[tddougla]

Ok, I'll start down the path of Tmeyer01. Usually the indication that I see is the refrigerator side warming up and then find the restriction in the cross over between the refrigerator and freezer. I will begin tearing down the freezer and looking at the heater, thermostat and drain. I didn't see a post concerning a timer and my board/control head looks the same as his.