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FIXED KRFF507ESS01 KitchenAid Refrigerator Too Cold

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dpreuss5

Premium Member
Joined
Feb 3, 2021
Messages
5
Location
United States
Model Number
KRFF507ESS01
Brand
KitchenAid
Age
1-5 years
I've owned the KitchenAid KRFF507ESS01 for about 3.5 years now. In the past I had the main board replaced under warranty and problems with the refrigerator evaporator frosting. The ADC was set to 8 hour cycle and I haven't had any frosting problems since this was done 4 months ago.

The current problem is that the refrigerator compartment is too cold. I have a mechanical refrigerator thermometer (purchased due to frosting problems) that shows the temperature is anywhere between 16-22 degrees. The temperature target is set at 38F. I've raised it up to the max setting of 40F but it makes no difference. The freezer is set at 0 and reads about 5F on the thermometer.

I took out all the covers to look at the refrigerator evaporator. The thermistor was in the right location according to the service bulletin but loosely attached under a zip tie. There was no spring clip like shown in the service bulletin. I couldn't tighten the zip tie further so I used some metallic tape to wrap the thermistor onto the tube. After putting everything back together, there was no change: the refrigerator compartment is still below freezing.

Logic is telling me it can be one of two things: the thermistor is bad, reading high temps, and the compressor believes it needs to run constantly. Second option is that the thermistor is right but something else is wrong, allowing the cooling to run constantly. After reading the detailed description from Jake in these forums about how the cooling system works (link here) I'm wondering if the 3-way valve is stuck and only the refrigerator compartment is getting refrigerant. But if I understand correctly, if the refrigerator is getting refrigerant for cooling, then the freezer is not. The fact that the freezer is 5F indicates it is getting some cooling. Also, if it was the 3-way valve and not the thermistor, it seems that it would still turn off at some point and the fan wouldn't circulate any air. I'm leaning towards a thermistor problem but it can only be replaced as an assembly with the fan and other connectors (cost >$85).

Has anybody else experienced this? Thanks for the feedback.
 

Jake

Appliance Tech - Admin
Staff member
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Aug 24, 2004
Messages
121,870
Location
McMullen Valley, Arizona
How long has the refrigerator section been between 16-22 degrees? This problem just started this week?

Here's your tech. data sheet: https://drive.google.com/file/d/1fdXgOoxWRTKLRRF_X1b_6YEyEI_SJdjr/view?usp=sharing

DO--->Service Test - 2: RC(refrigerator control) Thermistor
The board will check the resistance value of the thermistor and display the results on the Temp display (01 = pass, 02 = open, 03 = short).

If that passes DO--->Service Test - 3: Evaporator Fan and Air Baffle Motors
--->Control the RC and FC evaporator fan motors by depressing SW3 (01 = both fan motors OFF, 02 = FC fan ON).
--->Depress SW3 once to advance. Service Test 3 will flash quickly and advance to tests 13/23 very quickly. The result is RC fan ON, pantry air damper ON. Pantry air damper will open and close automatically
(13 = damper open, 23 = damper closed). Verify airflow inside pantry on left-hand side when damper is open (13 displayed). Airflow in pantry will cease when “23” is displayed.
--->Depress SW3 to advance to last step (04 = both RC and FC fans ON).

Jake
 

dpreuss5

Premium Member
Joined
Feb 3, 2021
Messages
5
Location
United States
Hello Jake,

Yes the problem just started two days ago. We noticed items freezing, starting with items on the top shelf but progressing to lower shelves over time. There is nothing in the refrigerator now, only items in the freezer and the temperature is still 16-22F.

Thanks for the tech sheet. I still have the original paper version that was stored under the door hinge also.

I ran through the tech sheet tests yesterday and got all "pass" on the thermistor tests. I re-ran the tests just now and the RC Thermistor is still a "pass".
I also checked the service test #3 and the fans and pantry damper are working as expected during each stage of the test.

Thanks,
Dave
 

dpreuss5

Premium Member
Joined
Feb 3, 2021
Messages
5
Location
United States
Jake, as additional information, I just ran the Service Test #4 for the compressor and valve. At the start of the test no fans are running and the compressor is not running.

Step 01 - initialize dual evap valve in home position - I couldn't observe or hear anything during this step
Step 02 - Close both RC and FC evap valves - no change -still cannot hear any noise and no change in air flow. Do you know how this is different than the "home position" in Step 01?
Step 03 - Turn compressor on - yes I could hear it turn on
Step 04 - Drive valve to RC position and turn on RC fan - yes the RC fan turns on and it blew cold air into the RC. No air flow was felt in the FC
Step 05 - Drive valve to FC position and turn on FC fan - yes the FC fan turned on and blew cold air. The RC fan turned off.

One of my original thoughts was that the 3-way valve was stuck in the RC position, but this test seems to indicate that it is not stuck and can switch between RC and FC cooling. Am I interpreting the results of this test the right way regarding the valve?

I also checked all the Thermistors again and all passed: FC (test 1), RC (test 2), Ice box (test 37), RC Evap (test 39) and Pantry (test 65).

Any additional thoughts are appreciated!

Dave
 

Jake

Appliance Tech - Admin
Staff member
Joined
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Messages
121,870
Location
McMullen Valley, Arizona
Ok Dave, I doubt its the 3 way valve causing this.

In fact , if all those tests passed then I don't know what can be causing this problem.

You will need to contact KitchenAid to come out at 1-800-422-1230 they can call the factory techline from your house, and they should know.

Jake
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
121,870
Location
McMullen Valley, Arizona
Glad to help Dave.(y)

Let us know what the tech says if you can please.:)

Jake
 

dpreuss5

Premium Member
Joined
Feb 3, 2021
Messages
5
Location
United States
I'm glad to share that I fixed the problem before the tech arrived. I had to wait over the weekend and had four days before the tech arrived so I decided to take off all the covers and look again at the evaporator and thermistors. All this time the refrigerator remained below freezing. I was looking for broken wires, loose connections or anything that just didn't look right.

What I discovered is that the RC evap thermistor was relocated to the wrong position. I didn't do it and I don't know when this happened. My last service call (to replace the main board) was about two years ago right when the service bulletin was released. The service bulletin shows that the thermistor should be removed from the top of the copper tubing loop but I don't think it's very clear which tube to move it to. Pictures 3 and 5 in the bulletin give you some clues, but the written description is not very clear. If you follow the copper loop tube, it leads to the rearward tube of the evaporator and it would make sense when moving the thermistor to mount it on the same stretch of tubing. In my case, the thermistor was mounted on the front tube which is the other end of the evaporator circuit.

I can't explain why it would have worked for two years and stopped now except for the fact that the thermistor was very loosely attached to the forward tube. Perhaps vibration over two years shifted it's position to the point that it started reading differently.

I moved the thermistor to the rearward tube, attached with a new cable tie and some metal HVAC tape to keep it in position. The refrigerator has been maintaining it's temperature for 24 hours now so this seemed to fix it.
 

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Jake

Appliance Tech - Admin
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Joined
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Messages
121,870
Location
McMullen Valley, Arizona
Excellent, glad you found the problem.(y)

Thanks for the update!

Jake
 
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