FIXED WRX986SIHZ01 Whirlpool Refrigerator - Evaporator coil top section frozen over.

[dbell1027]

Model Number

WRX986SIHZ01

Brand

Whirlpool

Age

1-5 years

My freezer drawer section fan started to make a lot of racket to I pulled the drawers out, back panel and found the evaporator coil top section frozen over. See attached photo.
I ran the service diagnostic mode service test-6 Defrost heater and got a (01 = bi-metal closed). I ran the service test-7 and got a (01=ADC on). I verified that the element was hot.

I noticed that test 7 stated that the defrost cycle would turn on every 8 hours of compressor run time. The frig is now 2.5 years old and what might cause the evap coil to freeze over if the defrost circuit is working.
I do know that excessive opening the drawer, and or a leaking gasket could contribute to the ice buildup. I also checked the door gasket and found it to be clean and free of defects or leaks.

I also checked the drawing and don't see any other device in the circuit that controls the defrost except the main controller itself, so I assume that the 8-hour timer is on the board?
Am I missing something or is there something else in the circuit that can cause the buildup. If not, then I will attribute the buildup to operator error and manually run the defrost cycle more frequently or as needed.

Thank you in advance.

Dan Bell

 

[dbell1027]

I've determined that the problem was that the clock timer on the motherboard has failed so I have ordered a new one.
I saw that one of the similar refrigerator/freezers had the exact issue and you recommended replacing the board.
Please let me know if you believe the issue lies elsewhere.
Thanks,
Dan

 

[Jake]

Hi Dan, When you open the freezer door do you hear that evaporator fan motor running?

Here's the evaporator(freezer) fan motor for your model:
W11032800 Motor-Evap


I'm attaching your tech. data sheet below.

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).

 

[dbell1027]

Good Morning Jake and thank you for the response.

The evap fan motor is running. In fact, the reason I originally suspected that there was a problem was because I could hear the fan blades hitting on the built-up ice.
I disassembled and removed all the drawers, grill and back panel. There was ice build-up on the left side of the panel which fell off as I removed it.
I Used a small heat gun to slowly melt all the ice that was shown in the attached photo.

I ran this test with the following results.
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. Results = OFF
(02 = FC fan on). Results = 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.
Results = I can hear the door opening and closing.
(13 = damper open), Results OPEN. Good air flow
(23 = damper closed). Results OPEN. Good air flow. The air flow does not stop.
Verify airflow inside pantry on left- hand side when damper is open (13 displayed). Results = Air flow good
Airflow in pantry will cease when “23” is displayed. Results = Air flow still flowing. I can hear a click sound from probably the control board calling for the door to close, but it stays open.
Depress SW3 to advance to last step (04 = both RC and FC fans on). Results = Both fans ON

Recommendations?

Dan

 

[Jake]

Ok Dan, then its a bad damper.

The refrigerator AIR DAMPER ASSEMBLY for your model is WPW10248595

 

[dbell1027]

Hi Jake,
Does the damper assy tie into the defrost timer circuit or is the damper the cause of ice buildup on the evap coils?
Dan

 

[Jake]

is the damper the cause of ice buildup on the evap coils?

Yes, that's exactly right, because the damper is not closing when it should be closing.

 

[dbell1027]

Hi Jake,
I've received the new damper ASSY and I've taken the shelves out, but I can't seem to remove the air tower.
Something is holding it at the bottom and the damper cover won't come off after removing the two screws.
Is the Styrofoam inside the tower supposed to be attached to the tower or is it supposed to come off separately?
I can't seem to find a video for this specific model. Do you know of one you could attach?

Thanks,

Dan

 

[dbell1027]

I found the following video and it showed how to take the tower off. It was stuck to the lower cover screws, but I got it off.

The thing I don't understand is that I have ice building up again on the evaporator cover in the freezer drawer.
The damper I bought is for the pantry drawer as shown on the left side of attached photo and it's working just fine during the service test 3, 13/23 open and close is working.
I originally thought it was routing air into the top of the tower duct which led me to believe the damper wasn't working. My bad.

So, this brings me back to why the ice is building up again on the freezer drawer evaporator cover plate and why the evaporator coils are freezing over again?
Is there another damper that routes air to the ice maker because that's the only place the freezer fan air goes to?

I can make the freezer defrost element heat up on service test 7, it works just fine. But I don't think it's going into defrost mode by itself at the 8-to-96-hour compressor run time cycle as shown on test 7. That function is run by the clock timer on the main control board. So, do I have a board problem because everything else seems to be working just fine?

Dan

 

[Jake]

Ok, if the fan motor is running and the defrost heater is working, then the control board is the culprit: https://www.repairclinic.com/PartDetail/Control-Board/W10843055/4383561

RepairClinic does credit you back $60 when you return the old board.

 

[dbell1027]

Hi Jake,
It's been several days, and the new main control board is doing it's job.
No more ice buildup on the freezer evap coil so the timer is working.
Thank you for your conformation on the issue and have a great day.
Cheers,
Dan

 

[Jake]

Excellent Dan, glad to hear the new main control board fixed it.

Thanks for the update!