FIXED Whirlpool Refrigerator WRB322DMBM00 Defrost problem

[gizmoakland]

Model Number

WRB322DMBM00

Brand

Whirlpool

Age

6-10 years

Bottom freezer Last couple of months continues frost/ice buildup in freezer. And the unit seems to be running all the time. When I put it into forced defrost, nothing seems to happen. The frost starts around the door on all sides.

I replaced the control board with a highly rated much less expensive Jazz board from Amazon and it did not fix the problem
I replaced the freezer gasket because the frost seems to start around the door. Not fixed.
I replaced the freezer thermistor with an OEM part and it is not fixed.
The refrigerator part seems to be fine.

What's next? Defrost heater and defrost thermostat?

Electrical novice...thus forgive the simplicity of this question... if I end up ohm testing a part, that is when the frig is unplugged, yes?

 

[Jake]

Here's the defrost thermostat for your model that comes with the wire harness:
Harns-Wire WPW10290745


The round black piece is the defrost thermostat. I always ohm test that for continuity while its frosty, your meter should read 0-1 ohm. Make sure you disconnect power to the refrigerator first before ohm testing.

If the defrost thermostat ohms good, then you will want to ohm test the defrost heater. Remove the two terminal ends to the defrost heater before ohm testing it.

Make sure you unplug your refrigerator first. Here's the video of how to ohm test your defrost heater:

Fridge Not Defrosting? Defrost Heater Testing, Repair | Repair Clinic

Refrigerator not defrosting? Freezing food? This video provides information on how to test a defrost heater on a refrigerator. Learn more from the experts at Repair Clinic.

www.anrdoezrs.net

Here's the freezer evaporator coil defrost heater for your model:
Defrost Heater Assembly WP12729128

If the defrost heater ohms good, then the only part left is the JAZZ main control board being the culprit.

Here's the OEM JAZZ control board for your model:
WPW10503278 Electronic Control Board

 

[gizmoakland]

Thanks for that. I did replace the control board already and still ice ice ice.

 

[gizmoakland]

Regarding the defrost thermostat, how do I ohm test it?

 

[Jake]

The round black piece is the defrost thermostat. I always ohm test that for continuity while its frosty, your meter should read 0-1 ohm. Make sure you disconnect power to the refrigerator first before ohm testing.

Ohm test it while its frosty.

If its not frosty--->"You can also manually close the defrost thermostat by using a can of compressed air dust cleaner. Hold the can upside down and carefully spray the thermostat to instantly super cool it."

Here's the multimeter to do that ohm test with. Or you can get a multimeter at any hardware store.

Watch this video below, it shows you how to use the multimeter:

 

[gizmoakland]

Okay, an update. I opened up the freezer guts. So much ice. Tons in the fins. And a big chunk right around the defrost thermostat. I steamed that all off and over the time of me working on it, all the ice melted. I tested the defrost heater for continuity and it worked. So the heater is fine. I put in another inexpensive control board replacement and ran the forced defrost. The defrost heater never heated up. The last piece then is the wiring harness that has the defrost thermostat. I could not figure out how to test that for continuity. I think I will simply replace it.

Does that sound logical?

 

[gizmoakland]

I guess my question is whether that harness is needed for the forced defrost mode. I'm assuming the control board is sending the signal to run the defrost heater. And when I'm doing a forced defrost, it should do it regardless of the defrost thermostat. Does the wiring harness that includes the thermostat connect to the heater?

 

[Jake]

I put in another inexpensive control board replacement and ran the forced defrost. The defrost heater never heated up.

The defrost thermostat has to be frosty for the defrost heater to come on.

Does the wiring harness that includes the thermostat connect to the heater?

Yes, its in the same circuit as the defrost heater.

 

[gizmoakland]

Well, it is fixed without putting in a new wiring harness.

Probably the control board? Not sure.

There was so much ice behind the panel including a big chunk right around the thermostat.

If the problem recurs, I'll be back. Thanks so much for your help! The only ice I want to see is in my icemaker!

 

[Jake]

Sounds good, thanks for the update.