596.72382411 Frost build up in freezer, mechanical noise

alan664

Premium Member
Joined
Mar 9, 2018
Messages
9
Location
Alabama
Model Number
596.72382
Brand
Sears Kenmore
Age
1-5 years
Local repair people don't work on this "LG / Samsung" model, apparently it's too complicated with it's two evaporator coils, sensors, and circuit boards. I haven't found any good info via Google on this model, which has french doors, a refrig drawer, and a freezer drawer on the bottom.

With frost buildup, I guess that means defrosting is not happening, which then means the heater element is bad, or some sensor is bad, or the controller board is bad. Anyone have any suggestions for what to test to determine where the problem is? Is there a way to force a defrost cycle, and is that a good test to run?
 

alan664

Premium Member
Joined
Mar 9, 2018
Messages
9
Location
Alabama
To clarify, the frost is on the back wall and on the evaporator coils that I can see through the back cover slots.
 

Jake

Appliance Tech - Admin
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Messages
102,195
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McMullen Valley, Arizona
Hi,

Kenmore 596 is made by Amana.:)

I located the defrost heater, its behind the back panel inside the freezer underneath the evaporator coil, but I couldn't find the defrost thermistor or defrost thermostat, but it should be clipped to the top coil of the evaporator.

Here's the defrost heater for your model: Defrost Heater Assembly WP12729128

Here's the video that shows you how to ohm test it: Fridge Not Defrosting? Defrost Heater Testing

Make sure the refrigerator is unplugged first!

Jake
 

alan664

Premium Member
Joined
Mar 9, 2018
Messages
9
Location
Alabama
We did find a local tech to respond a day or so later, and he said the issue was probably that the door didn't completely close and seal for a time, leading to the ice buildup, and to just empty and turn it off for 24 hours for a full defrost. We did that and it seemed to work for months, but the ice build up has occurred about 4 times since, so about every 3 months. So far we've just done the full defrost each time. If a component was bad, could it take 3 months for ice to build up to the point of reducing cooling and fan blades hitting the ice?

But a new problem with our current instance of buildup, is that there was also a pond of water under the crisper. I've started another thread on that, which is due to a cracked (actually broken into 5 pieces) drain pan.
 

Jake

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Thanks for the update!

If a component was bad, could it take 3 months for ice to build up to the point of reducing cooling and fan blades hitting the ice?
Yes, possibly the defrost thermostat, which I just located, it comes with the evaporator fan motor. The defrost thermostat is the black circular part that clips to the top of your evaporator coil.

The way to test the defrost thermostat is to unplug the refrigerator from the wall outlet, then pull that plastic electrical connector out that it goes to, it unsnaps, then use your multimeter and set it on 200 ohms and ohm test the defrost thermostat WHILE ITS FROSTY, if it's not frosty you will not get a proper reading. If your meter doesn't change numbers while your ohm testing it, then its bad. It should read 0 ohms WHILE FROSTY.:)

The wires you will need to ohm test from that electrical connector are the orange and brown ones.

Here's the defrost thermostat and evaporator fan motor for your model:


Jake
 

Jake

Appliance Tech - Admin
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Wait, are you referring to frost build-up on the evaporator coil inside the freezer section? Or refrigerator section?

That evaporator fan motor with the defrost thermostat is for the freezer section.

If your getting frost build-up in the refrigerator section evaporator coil, that one does NOT have a heater, it defrosts per the evaporator fan motor in the refrigerator section. Make sure that fan is running all the time, if not, then its bad.

Look at page 5-9 and 5-10 here: https://www.dropbox.com/s/s5wx9d9xppw3wry/R-114 JOB AID W10444924.pdf?dl=0

It will show you how, you may have to remove the Air Tower and the Deli Drawer first, Deli Drawer removal is on 5-7 and 5-8.

Here's the evaporator fan motor for the refrigerator section for your model:
W10633627 Motor-Evap


Jake
 

alan664

Premium Member
Joined
Mar 9, 2018
Messages
9
Location
Alabama
After my last round it limped along, but ice cream is too soft again. Refrig temp is 45, freeze is 25. Getting ice buildup on the freezer evap coil again.

I thank you, Jake, greatly for the PDF manual; I was able to access and replace my broken refrig evaporator drip pan with that guide. My model must be a year newer (copyright on the tech data sheet is 2014, the PDF has 2013), but the sample tech sheet in the PDF mostly matches my actual sheet's wiring diagram and service tests.

I ran service test 6, and it showed 01 (bi-metal closed) for about 10 minutes. Down on the floor watching the drain tube I could see 5 to 10 drops per second, so the defrost heater and bi-metal defrost thermostat at least partially work. After about 10 minutes the drip rate slowed, and the display changed to 02 (bi-metal open). There was no longer any ice/frost visible through the slots of the FC evaporator cover. But 24 hours later frost was again visible through the slots.

The PDF goes into detail on how it cools the refrig, then the freezer, and defrosts the refrig with just a fan, but it doesn't mention anything about the freezer defrosting. Service test 7 is not a test, but is used to change the defrost mode between ADC (automatic defrost control?) and basic (8 hour timer). I changed it to basic, and still have ice build up.

So, with the (partial?) success of test 6, do you still think it's the defrost thermostat? If so I'll order that fan with the defrost thermostat included in it's harness. Do you get a commission on the part if I follow the link in your June 15 post? If so I'll buy from there to support your good work with this site. If not, I may shop around.
 

Jake

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When you say frost build up is it so bad that you can't see the evaporator coil at all? Because you should have a thin layer of frost on ALL the coils from TOP to BOTTOM.

If you can take a photo of the frost on your evaporator coil that would help me to see what's going on.

Jake
 

alan664

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Joined
Mar 9, 2018
Messages
9
Location
Alabama
freezer_frost.jpg

This is the view with the cover still on. More frost in the center, and some near the top on the cover itself. I haven't emptied the freezer yet; if you need to see the whole coil, I'll empty it and remove the drawers and cover.
 

Jake

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Yes, I need to see the entire evaporator coil.:)

Jake
 

Jake

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Ok, that is very weird, defrost it all and put the evaporator cover back in place and let it run for 24 hours then take another photo of it.

Jake
 

alan664

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Joined
Mar 9, 2018
Messages
9
Location
Alabama
I've done that cycle about 8 times over the months. Does the location of the first ice give a big clue to what the problem might be?

Or is it almost certainly the bimetal defrost thermostat?
 

Jake

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I really don't know, I've never seen a frost pattern like that before. You'll need to have Sears come out to see what's going on.

Jake
 
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