• Please note, some of the links on our site are affiliate links (Learn More)

FIXED KRFC704FPS KitchenAid fridge RC evaporator completely iced up

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
Model Number
KRFC704FPS
Brand
KitchenAid
Age
1-5 years
Hi all,

First, this forum is the absolute best place to find debug info on appliances, so thank you to everyone that makes that happen.

A few months ago we noticed water in the basement under our fridge but didn't connect the issue to the fridge until the RC warmed up. I pulled the shelves out and thawed the RC evaporator, which was completely iced up. A big block of ice. Here's a non-exhaustive list of debug steps I've taken:
  • ran through diagnostics, no SH or OP. Temps all seemed OK.
  • checked that the thermistor was in the correct spot according to other posts on the forum (it was)
  • tested the resistance on the thermistor, 7.6kΩ at 40°F and 8.2kΩ at 35°F
  • tried to test the evaporator fan DC voltage but was unable to (not sure *exactly* how to do this, tried to follow the advice in a post here)
The latest rev of the control board is being shipped right now but I'm not sold on swapping it out quite yet.

I plugged everything back in and ran the fridge for 2 days, then pulled the evaporator cover off to check things out and there was already some ice buildup. The black foam pad on the inside of the Styrofoam cover was saturated with water. Culprits I can think of:
  • sync motor isn't opening the damper
  • evaporator fan is bad (sometimes something makes a little noise but it might be the damper opening, not sure)
  • compressor issue
  • bad control board
Any other ideas? Thanks for helping me troubleshoot this! I'll be happy to provide more info if needed.

Jesse
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
43,640
Location
Murray, Utah 84107, United States
Keep both “—” and “—” temperature buttons pressed for 3 seconds. Countdown will display and a chime will play upon entry into Service mode.

Enter Key = “Drawer” button

Increment Key = “+” button on the upper display

Decrement Key = “-“ button on the upper display

Back Key = “Max Cool” button

To Exit Service diagnostics, use “Max Cool” Key to back out of functional test. Press and hold “-” and “-” temperature buttons simultaneously for 3 seconds.

Service Test #00 Exit Service Mode:
This step is an alternative method to exit service mode and return to Normal Operation.

Service Test #57 RC Fan Test
When entering this service test, the Refrigerator Compartment fan turns on. The display shows “ON.” When leaving this service test, the refrigerator fan turns off.
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
Thanks Rick!

Service Test #57 RC Fan Test: fan turned right on!

I should clarify, I wasn't able to test the voltage across the fan, but I guess I didn't need to.
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
43,640
Location
Murray, Utah 84107, United States
Is the frost pattern on the evaporator partial or on all the coils? You probably noticed the evaporator is black. That's because it doesn't use a defrost heater. When the FF compartment is calling for cooling the control checks the thermistor before the compressor turns on. If the control suspects the temp is too cold and there's frost on the coils, it will turn the FF fan on for up to 10 minutes (to ensure the coils are defrosted) before starting the compressor. Make sure there are no air leaks around the cover and check the foam seal is in place.
W11167902-Cover.jpg
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
I believe it was partial. I checked the seal and it looks fine. It didn't look like there were any gaps between the cover and the back of the fridge, but it's kinda hard to tell.

I had to put the food back in. What would my next steps be to debug this? Thanks again for your help!
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
43,640
Location
Murray, Utah 84107, United States
I believe it was partial.
Leave the machine plugged in and running, remove the cover, take a pic of the coils and post it here. Does the refrigerator cycle off and on or does it run continuously.
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
I jumped the gun on putting everything back. I'll have to wait until Friday or next weekend to take it apart again, then will post pics.
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
It seems like it runs continuously, but it's so quiet that is hard to tell when it's in the cabinets. Is there another way to tell?
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
What's the timeline on checking things again? Should I give it a month? Is there a way to keep an eye on things without having to pull the fridge apart? Thanks!
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
Well, just as we were about to walk out the door to go camping for 2 nights, we saw a small puddle. I ripped the fridge apart and the right half of the RC evaporator was iced up.

AM-JKLVV4KuK5UPYYsbiP1NzLCtBfD3PWctf40WN2JXFGKpGKz4-cVP0LwZo6ZLD2e_4g6E63RjzD5p5b74NuWkTbmXMo4NiMnaSrb2wFFFhwieQfpciPlcdZtFR5U4gZVDuzLk2ZBf8QzGPNKtDxiR4lpS8fw=w952-h714-no


I'm not sure what to do now besides either replace the control board (which we have the latest compatible model already here, I was avoiding taking it out of the box) or call in service. Ideas? Thanks!
 

jc00ke

Premium Member
Joined
Aug 6, 2021
Messages
16
Location
Portland, OR
I defrosted the RC evaporator coil, plugged everything back in and turned it on... water started dripping:

1629672056430.png


It was probably 1/4 cup, but pretty soon after plugging it back in. I've turned the water supply & ice maker off just in case.

I also took the back panel off but could not see any evidence of water (I'm guessing that's the FC evaporator anyway)
 
Top