KitchenAid Refrigerator KSF26C4XYY03, not defrosting

[silentwatcher]

Model Number

KSF26C4XYY03

Brand

KitchenAid

Age

6-10 years

All, I have a KitchenAid side-by-side refrigerator. Its model number is KSF26C4XYY03. It recently failed to defrost and the built-up frost/ice around the evaporator coil caused the temperature in the RC part of temperature rise, as little cold air flow from FC to RC side.

I changed a new bimetal thermostat. However, the issue remains. Around 0F in the FC (by using a portable thermostat to read), I ran the Service Test - 6: Defrost Heater/Bi-metal. The display sometimes shows always 02 as the result, while sometimes shows 01 for a couple of seconds, then 02 again. I ran force defrost and it could melt off some frost but not all before the defrost cycle ends. The defrost heater felt warm/hot but not scorching hot.

Could you kindly advise what might go wrong or what additional diagnosis can help find the culprit(s)?

Many thanks.

 

[silentwatcher]

Forgot to mention the following additional tests:
1. Had the new bimetal thermostat (WPW10225581) removed from wires of FC, placed in a freezer till around 0F or colder, the continuity test showed that it was continued.
2.

TEST	RESULT
01 FC Thermistor	01 pass
02 RC Thermistor	01 pass
03 Evap fan motors	All normal
06 Defrost/Bimetal	02 open
39 Ref evap thermistor	N/A Auto passed - not able to run this test. the number is skipped from 38 to 42 directly.

3. Installed the new bimetal thermostat back in FC, ran till the temperature in FC around 0F or lower, ran the Service Test - 6: Defrost Heater/Bi-metal and received the code 02, while it says "Below 17+/-3°F - Closed" in the service paper coming with the refrigerator. If pushing the +/- to change the tests by retesting #6, it could show 01 as a result in some retests.

Could it be issues in FC/RC thermistors or the control board, etc.?

 

[Jake]

Sounds like the control board is possibly malfunctioning.

Here's the control board for your model:
Refrigerator Control Board W11088499


Lets first verify your new defrost thermostat is good.

You can ohm test the defrost thermostat, this is how we ohm test the defrost thermostat, read below.

Here's the multimeter I use:
Multimeter DM10T


You can get a multimeter at any hardware store too.

You would need to ohm test the defrost thermostat for continuity while its still covered in frost. Unplug your refrigerator first! If the defrost thermostat goes into the quick disconnect electrical connecter, just unsnap that quick disconnector and ohm test it in that quick disconnect electrical connecter. Its very easy, just follow the wires back from it, should be the PINK wire and BROWN wire, then put your meter probes in each of the two wires in the electrical connecter and see if the meter numbers move. Set the meter on the lowest ohms of resistance.

If the defrost thermostat is not frosty, you can still test it in a cup of ice water, watch the video below. You'd need to keep the defrost thermostat in the cup of ice water at least 5 minutes before ohm testing it.

Here's your (bi-metal)defrost thermostat for your model:
WPW10225581 Defrost Thermostat


Watch this video to ohm test your defrost thermostat if yours is NOT frosty:

Jake

 

[silentwatcher]

Thank you so much for valuable information. I did the separate test on the bimetal thermostat by the following:
1. uninstall the newly installed new one and put it into a freezer to ensure it will be below or around 0F
2. test continuity of the bimetal thermostat around the cold temperature. The continuity is through. This is as expected.
3. leave it in room temperature for a couple of minutes, then test continuity. The continuity shows not through. This is also as expected.

Changed a new W11088499. The Service Test Defrost/Bimetal shows 01/close when the temperature is cold around 0F, as comparing to the test result from the old board in my previous post.

Will report back after 1 to 2 weeks if the refrigerator runs smoothly with the new board.

On the other hand, does the Whirlpool Refrigerator Thermistor (WP2188820) in the FC have any impact to the defrost process?

Thank you for your valuable help.

 

[Jake]

Yes, both the new and old defrost thermostat(bimetal) ohm test good. We use process of elimination to check the auto-defrost parts. If the defrost thermostat(bimetal) and defrost heater both ohm test good, then all it can be is the control board malfunctioning.

On the other hand, does the Whirlpool Refrigerator Thermistor (WP2188820) in the FC have any impact to the defrost process?

Nope, none.

Jake