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FIXED KRFF507ESS01 Frost Build-Up in Bottom of Refrigerator Compartment

racerfern

Premium Member
Joined
May 4, 2020
Messages
6
Location
Baldwin NY
After pushing more buttons than I could imagine, I got to the setting for Auto defrost. The technician that was here last time said he changed the setting. However, it was set to "01" Auto Defrost or ADC" which is somewhere between 8 and 96 hours whenever needed. I set it to "02" for defrost every 8 hours. I confirmed by exiting Service Diagnostics and re-entering. It went to "02" instead of "01".

I still want the technician that's coming on Thursday to verify the thermistor is located properly because why should I have to run a cycle every 8 hours, especially if not needed. I will report back.
 

TIMMMY

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Jun 13, 2020
Messages
1
Location
pittsburgh
This blog is a life saver!..I have same problem kitchenaid KRFF507ESS01. have to defrost every couple months due to frost behind meat/cheese drawer so bad you can't close drawer. Did the tech code mode and test 6 read "01" bimetal closed/sensor short. Do I need a new sensor? Now the problem also starts with a humming fan that seems to be coming from the top back vent...it that due to the frosted over bottom vent?
 

Jake

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McMullen Valley, Arizona
Service Test - 6: Defrost Heater/Bi-Metal
NOTE: If bi-metal is open, it will need to be bypassed for heater to operate.
Heater should be ON. Display will be blank until a valid reading is displayed
(01 = bi-metal closed, 02 = bi-metal open).

01=bi-metal closed, it doesn't say short. This test 6 ONLY applies to your freezer bi-metal, not your refrigerator bi-metal, because your refrigerator evaporator does not use a defrost heater to defrost the coils, it uses the refrigerator fan.:)

I'm attaching the tech data sheet for this model below.

The first thing you will want to do is post your serial number to see if you need to relocate your thermistor per that service bulletin I posted in post #4 of this thread.

Then access that fan motor and see if its running.

Jake
 

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racerfern

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May 4, 2020
Messages
6
Location
Baldwin NY
Well, the tech replaced the main board in the back of the fridge. It's still building up ice but possibly not as quickly. However as of two days ago I have a relatively loud whirring sound coming from the fridge, top section about the middle. It could sound like a compressor or a fan. Sound is on just about 24/7 but not quite. Cooling is good at this point though the lowest drawer, cheese etc is quite cold even though it's set to 40. Things aren't freezing anywhere but I have to believe something is going to rear its ugly head. The unit will be one year old in August so I really want to get this resolved ASAP.
 

racerfern

Premium Member
Joined
May 4, 2020
Messages
6
Location
Baldwin NY
Hopefully this is the final post on this issue, by me anyways. Shortly after the last post the ice suddenly started building up. They wouldn't even come out until they ordered and received a replacement thermistor.

After warranty replaced the thermistor (which should have been repositioned or replaced on the first visit except they probably had to stretch the warranty claim as much as possible) I defrosted the refrigerator once again.

It's been almost two weeks and there isn't even a hint of ice buildup.

Since I couldn't be home for any of the repair visits, my guess is that had they checked the location of the thermistor on the first visit, the problem would have been solved right then and there.

One final note:
When I made my service complaint just prior to the replacement of the thermistor, the person I spoke with was very understanding and sympathetic. He could sense my frustration and he immediately offered an extension of the factory warranty for an additional six months at no charge. I asked that they email or mail me a confirmation and he said they couldn't do that. It was noted in their system and that was that. I guess that way there's no proof of this form of goodwill.
Let's hope I don't need it.
 

Boonesmith20

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Joined
Jul 20, 2020
Messages
1
Location
Maryland
Model number KRFF507ESS. About a year ago, I had frost build up behind the drawer in the refrigerator. I unplugged and defrosted it and everything worked fine. A few days ago the ice maker, fridge, and freezer all quit working. The upper evaporator fan works, the condenser fan works, but the lower evaporator fan (in the bottom freezer area) does not work. Does anyone have the part number for the lower freezer evaporator fan? It says part no. W10728094 on the fan motor, but I believe I saw it as part #2684741 also.
Additionally, should I replace the thermistor also? Could relocating/ replacing the thermistor prevent further frost build up? Any help would be much appreciated.
 

EDaryl

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Joined
Jul 21, 2020
Messages
1
Location
College Station, TX
Thanks, everyone for sharing your experiences! This thread has been invaluable.

I'm facing a similar problem with my 2016 KRFF707ESS01 (SN K63726415). The refrigerator stopped cooling (first time since owning it), so I called and requested warranty service and cleaned the evaporator coils. I defrosted it and noticed that my thermistor probably needs to be repositioned. The diagnostics all seem to come back OK, but I'm not a technician. I'm curious if it would take three years for this thermistor placement problem to cause the cooling failure or if I should be concerned about other causes. I'm also curious about the plastic bag with gray goop on the coil. What is it? Should I be concerned that the bag isn't sealed and some of the gray stuff has leaked out? I've also noticed that my freezer (whose coils seems to be frost-free from a visual inspection without removing the drawers) is in the 11-15 degree range despite being set to 0.
 

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Jake

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Model number KRFF507ESS. About a year ago, I had frost build up behind the drawer in the refrigerator. I unplugged and defrosted it and everything worked fine. A few days ago the ice maker, fridge, and freezer all quit working. The upper evaporator fan works, the condenser fan works, but the lower evaporator fan (in the bottom freezer area) does not work. Does anyone have the part number for the lower freezer evaporator fan? It says part no. W10728094 on the fan motor, but I believe I saw it as part #2684741 also.
Additionally, should I replace the thermistor also? Could relocating/ replacing the thermistor prevent further frost build up? Any help would be much appreciated.
Here's the FREEZER evaporator fan motor for your model:
W11032800 Motor-Evap

It comes as a kit which includes the freezer evaporator defrost thermostat.

Jake
 

Jake

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Messages
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Thanks, everyone for sharing your experiences! This thread has been invaluable.

I'm facing a similar problem with my 2016 KRFF707ESS01 (SN K63726415). The refrigerator stopped cooling (first time since owning it), so I called and requested warranty service and cleaned the evaporator coils. I defrosted it and noticed that my thermistor probably needs to be repositioned. The diagnostics all seem to come back OK, but I'm not a technician. I'm curious if it would take three years for this thermistor placement problem to cause the cooling failure or if I should be concerned about other causes. I'm also curious about the plastic bag with gray goop on the coil. What is it? Should I be concerned that the bag isn't sealed and some of the gray stuff has leaked out? I've also noticed that my freezer (whose coils seems to be frost-free from a visual inspection without removing the drawers) is in the 11-15 degree range despite being set to 0.
Yes, it DOES list your model in that service bulletin, AND your serial number IS WITHIN RANGE--->Serial Numbers: K212 to K704.
--->Here's that service bulletin: https://www.dropbox.com/s/2davtxcm0ss5szz/frostbuildup.pdf?dl=0
Yes, it could work fine for 3 years, then start doing this out of the blue, so you will need to follow the instructions and relocate it to where it says to.

Jake
 

leespa

Premium Member
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Sep 6, 2020
Messages
3
Location
Saskatoon, SK
Hi All,

I have Kitchenaid KRFF707ESS01 K63726425 so just 10 units behind EDaryl. I am presently defrosting the unplugged fridge and will check thermistor position, etc. Fridge was new in July 2017 and issue free until late 2019. Since that time this will be the third time having to defrost it in last year. Waiting for ice to melt so I can get panel over the fridge evap assembly free again.

.IMG_20200906_112032.jpg
IMG_20200905_093059.jpg

Part 2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
IMG_20200906_124817.jpg
So looks like defrost thermistor needs to be moved. I will do that once done defrosting, drying out.

Question: is there a way to force the Evap Fan to run in order to ensure it is working?
 
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leespa

Premium Member
Joined
Sep 6, 2020
Messages
3
Location
Saskatoon, SK
Part 3
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- RC thermistor relocated as per service bulletin
-- RC thermistor also registers as a PASS = 01 thru the service mode

-- Evap Fan working.

As per last two times fridge is noticeably cooler as soon as ice all cleared.

Here's hoping this fixes the issue.
Thanks for all the great info on this site.

IMG_20200906_150206.jpg

IMG_20200906_150157.jpg
 
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Jake

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Forcing the evaporator fan motor to run--->Service Test - 3: Evaporator Fan and Air Baffle Motors

Here's the refrigerator evaporator fan motor for your model:
W11033168 Fan Motor & Harness


Glad to hear it ran fine, yes hopefully moving the thermistor per the service bulletin fixes yours too.:)

Jake
 

leespa

Premium Member
Joined
Sep 6, 2020
Messages
3
Location
Saskatoon, SK
I'm rather skeptical that relocating the sensor is going to magically fix this issue, but time will tell. The way the thermistor was mounted originally looks like it would have been measuring ambient, since not even in contact with the tubing.

Definitely now know to look for future fridges with dedicated heater elements for defrost. This idea that a small internal fan will properly defrost seems rather mickey mouse to me.

Thanks again for all the resources on here as well.
 

Jake

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Yes, I don't like dual evaporators myself either mainly because of this reason too.

Simple is best with just one evaporator in the freezer to cool both sections.

The freezer evaporator ALWAYS has the defrost heater.:)

Jake
 

Dangle

Member
Joined
Oct 4, 2020
Messages
1
Location
Canada
I have the same issue and when I removed the crisper drawers there was a lot of ice covering the vents.
I’ve read the the post here but don’t understand how I get the fridge compartment into defrost mode?
Please advise. My unit is 4 years old and this is the first issue. Also how do you set the defrost to occur more often?
 

Jake

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Messages
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Read the tech data sheet in Post #23 and it tells you how.

Jake
 
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