FIXED KitchenAid Refrigerator KRMF706ESS00 - Freezer coils Iceing up

[mproto]

Model Number

KRMF706ESS00

Brand

KitchenAid

Age

6-10 years

Had the freezer coils freeze up so bad it impeded the FC Evap. motor which in turned threw a PO error on the service panel.
Disassembled the freezer section to expose the coils, motor, etc.
Took a heat gun and melted all of the frost and solid ice in and around the coils and other components.
With now all of the ice gone I put the freezer door back on and let the unit run overnight.
Once again I could see an accumulation of frost in and around the coils... (Note: no service errors displayed)

So ran the following..:
Service Test (ST) - #3 Evaporator Fan Motor and Air Baffle Motor : both RC and FC motors functioned fine.
ST # 6 - Defrost Heater/Bimetal/Sensor: test = 3 (pass)
ST # 37 - 37 Ice Box Thermistor: Results 01 (pass)
ST # 6 - Defrost Heater/Bimetal/Sensor: left in mode for 5 min. the heating element did not feel warm.
ST # 38 - Forced Defrost Mode: Left in Sh state for 20 min until reset - heating element did not feel warm
Measured the continuity of the heating element itself w/ muliti-meter. Passed continuity test.
I will make sure that the drain hose is not restricted ...
But ...I suppose this leaves the Control board?
Is there any other tests recommended?
What is the latest control board part number now?

 

[Dan O.]

let the unit run overnight. Once again I could see an accumulation of frost in and around the coils.

Just from running overnight??? It would usually take up to a week for a defrosting problem to cause issues.

Please post an actual photo of the frost accumulation. It can be an important clue as to what is actually going on.


Dan O.

 

[mproto]

Since the post I already thawed out the coil section I could not take any images but what I did notice is that there was still ice accumulated on the bottom metal drip tray be low the coils. I also inspected the rubber drain tube on the back and insured it was cleared ... cleaned out w/ snake and hot H2O. I stuck a snake up the drain tube port where the drain tube attaches and it appears it is still blocked by ice (see the attached image) ... I will see that this is free of ice before I retest.
At any rate since I did not feel and heat on the defroster tube as described in the previous post upon the tests I ran, should I be considering getting a replacement control board? Hate to spend $300 for nothing if I don't need to on this project .. unless the board is returnable of course..

 

[Dan O.]

Ice in the defrost water drain trough has nothing to do with defrosting. If ice is actually inside the drain line could require the fridge to be turned OFF with the doors left open for 12-24 hour to fully melt it. (The fridge cabinet is insulated so any ice will melt very slowly.)

I would further suggest that once the defrost water drain line is *totally* unfrozen, try blowing through it with compressed air from the bottom up. Food stuffs or just residue can build up in the drain line slowing draining and resulting in a backup that eventually freezes the drain closed. (Put a cloth over the drain hole in the freezer as all sorts of residue could be blown out, creating a mess if not caught.)

At any rate since I did not feel and heat on the defroster tube

Depending on the temperature it was at at the time, that could be as expected. There are usually precautions to prevent the defrost heater from coming on when the fridge gets (or is) warm. Was it warm at the time you tried to initiate it??

should I be considering getting a replacement control board?

I don't suggest anyone replace parts on a guess.

unless the board is returnable of course.

It won't be. Electrical parts are not for trial and error.

LINK > Applaince411 Tips: Don't be surprised!


Post a photo of the frost/ice buildup when it occurs again and we'll try to suggest a course of action at that time.

JMO

Dan O.

 

[mproto]

Depending on the temperature it was at at the time, that could be as expected. There are usually precautions to prevent the defrost heater from coming on when the fridge gets (or is) warm. Was it warm at the time you tried to initiate it??

The temperature at the time was cold as the freezer was just turned off when the Service tests were run...
Are you indicating above if you perform a forced defrost (i.e. heating up the defrost heater in service mode - Service Test #38) that if the the freezer area is room temp, it may not heat up even in service test?

 

[Dan O.]

The temperature at the time was cold as the freezer was just turned off when the Service tests were run.

Than that should rule it out as the cause of the heater not coming on.

if the the freezer area is room temp, it may not heat up even in service test?

That can be the case however I don't know about on your specific model but your previous statement rules that out anyway.


Dan O.

 

[mproto]

That can be the case however I don't know about on your specific model but your previous statement rules that out anyway.

the specific model is in the posting title (FYI)

 

[Jake]

Took a heat gun and melted all of the frost and solid ice in and around the coils and other components.

The most important TEST to run when you have a defrost problem is TEST 6. The defrost thermistor MUST be FROSTY for the heating element to come on.

Service Test - 6 Defrost Heater/Bimetal/Sensor
--->Switch on the defrost heater, wait 0.5 seconds and read the status of bimetal/sensor. Display will be blank until a valid reading is displayed (01 = Bimetal Closed/Sensor Short, 02 = Bimetal Open/Sensor Open, 03 = Pass (only in case a defrost sensor is present)

So run TEST 6 while the evaporator coil is frosted. Then let it stay in TEST 6 for awhile and after 5 minutes feel for heat from the defrost heating element at the bottom of your evaporator coil.

Look here:

FIXED - KRMF706ESS01 KitchenAid Refrigerator - not defrosting, freezing up, no long defrost option

Hello. I've lurked on this forum for a while and used its info to fix several issues. Thanks for that! I've got a KRMF706ESS01 with fan noise in the freezer. The FC fan and motor seem good. The fan was hitting ice as the FC Evap Coil was frozen over. I defrosted it completely (a couple of...

www.applianceblog.com

Then look here, it got hot:

FIXED - KRMF706ESS01 KitchenAid Refrigerator - not defrosting, freezing up, no long defrost option

Performed test #6 and 03 is what shows up. I attached picture for verification. Also did a test #56 and an E2 appears. Error code saying motor lost position. What is the remedy for that one. In the process of taking freezer door and guts out now.

www.applianceblog.com

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

 

[mproto]

The defrost thermistor MUST be FROSTY for the heating element to come on.

jake.. Thank you for the follow-up ... this is a very important point to know...
Cheers

 

[Jake]

If the heating element still does not come on when its frosty, then it could be a bad IN-LINE THERMAL FUSE.

Read here about the IN-LINE THERMAL FUSE:

FIXED - KRMF706ESS01 KitchenAid Refrigerator - Freezer is building up ice

diagnostic service code 7 missing

www.applianceblog.com

On this model the defrost thermistor and inline thermal fuse comes only with the F(freezer)C(compartment) evaporator fan motor assembly. Its in-stock here: Motor-Evap W11249952

 

[mproto]

To Jake ... Appliance Tech - Admin

ok ... here is the latest ... I completely manually defrosted my freezer coils approx 2-3 weeks ago because they were freezing up.
All seemed fine until I started to hear the freezer ciol fan making noise again due to the collection of ice. I once again went thru all of the TSing steps listed below;
Service Test (ST) - #3 Evaporator Fan Motor and Air Baffle Motor : both RC and FC motors functioned fine. but of course the FC fan made noise
ST # 6 - Defrost Heater/Bimetal/Sensor: test = 3 (pass)
ST # 37 - 37 Ice Box Thermistor: Results 01 (pass)
ST # 6 - Defrost Heater/Bimetal/Sensor: left in mode for 5 min. the heating element did not feel warm.
ST # 38 - Forced Defrost Mode: Left in Sh state for 20 min until reset - heating element did not feel warm (tried this method 3 times in a row)
Measured the continuity of the heating element itself w/ multimeter. Passed continuity test.
ST # 77 - Defrost Thermistor result = 01 Passed
Made sure that the drain hose is not restricted ...
At this point I am suspecting the Control board?
Is there a way to test the board somehow? as they are not returnable

 

[Jake]

Hi,

Since the defrost heater and defrost thermistor both test good, then the problem is the main control board.

Look at this thread:

FIXED - KRMF706ESS01 Freezer coils constantly freezing over, all parts test "OK". Other issues as well.

Good afternoon, thank you for having this awesome forum. I've been fighting this issue over a year with no luck. I've got a KRMF706ESS01 that will consistently freeze the freezer evap coils. The first time this happened, we noticed noise in the freezer cabinet. It turned out to be the fan...

www.applianceblog.com

Your model uses the exact same main control board.

Here's the main control board for your model:
Refrigerator Control Board WPW10675033

Is there a way to test the board somehow? as they are not returnable

Yes, you can. I'm attaching your tech. data sheet below.

In TEST 6 see if you get 115 volts from these 2 connector pins:

 

[mproto]

Thx Jake .. I also see there are 2 thermo-fuses.. - but I won't ask why ... yet

 

[mproto]

Jake ... made the measurements on the Control board with the Service Test #6 mode enabled.
Front display shows - 01
On Control board P2-7, voltage reads 33.5 VAC. (not the expected 115 VAC)

 

[Jake]

Then your main control board is the culprit.

 

[mproto]

OK figured the C-Brd was the issue ... so my new question is: in reading this and other forums, the control board is the issue w/ icing up FC issues alot on this model. Do you know what specifically is the failure component on the board? eg. relay, eeprom, other electronic component etc. The reason why I ask is because I'm wondering if KitchenAid has made running changes to their circuit boards identified by revisions (eg. rev a,b,c etc?) I certainly do not want a board that doesn't have the component failure remedied.

thx

 

[mproto]

Jake .. please reference the previous messages #11 thru #16. (and the attached image)
I had to manually defrost the FC coils as they were caked w/ frost and Ice. In doing so I went ahead and removed the fan assembly to dbl. check the Thermo- fuses (TF)
I measured continuity on the TF which had the black wire attached from the single Molex plug to the appropriate pin on the multi-Molex plug (brown wire pin 7).
However when I measured the other TF which was connected to the white wire it read open (at pin 9 on the multi-Molex plug). I'm dbl. checking to make sure both TFs should show continuity (at room temp).
Now since Control board P2-7 did not show 115 VAC when Service mode # 6 was enabled I'm thinking that there may be 2 issues here. A bad TF (on the white wire) AND a bad Control board. - Any input ??

 

[Jake]

Do you know what specifically is the failure component on the board? eg. relay, eeprom, other electronic component etc.

No, I sure don't know what causes the control board to fail.

Now since Control board P2-7 did not show 115 VAC when Service mode # 6 was enabled I'm thinking that there may be 2 issues here. A bad TF (on the white wire) AND a bad Control board. - Any input ??

Yes, that indicates you will need to order both the main control board and Motor-Evap W11249952

 

[mproto]

Yes, that indicates you will need to order both the main control board and Motor-Evap W11249952

when it rains it pours ...
Cheers

 

[Jake]

Yes, I know what you mean.

Let us know how it goes.