Whirlpool Refrigerator WRX988SIBM03 defrost issues

[bblancha]

Model Number

WRX988SIBM03

Brand

Whirlpool

Age

6-10 years

Sorry for posting a new thread. I've been searching but can't seem to find the answers I'm looking for. Thanks in advance.

Whirlpool refrigerator WRX988SIBM03

1. Freezer won't defrost without forcing into defrost mode (test 38? typing from memory) and by jumping the thermostat.

I replaced thermostat. Didn't correct. Freezer will defrost by forcing and jumping thermostat only.

2. Noticed Ice build up behind deli drawer. Tested fan and damper. Felt aiflow from the right damper facing the front of fridge (drivers side) only. very light airflow and could hear the fan running. Tested fan on P14, 3 and 4 read 8.4VDC.

Could it be possible that the evap fan in the RC has failed, and i got a bad thermostat from Whirlpool. I tested the thermostat by placing it in another freezer and it closed after frosting before installing.
Thanks!

 

[Jake]

Service Test - 38: Forced Defrost Mode
--->Set the forced defrost mode by selecting SW3 (OF = no forced defrost, Sh = short defrost, Lo = long defrost).
NOTE: If a forced defrost is selected, defrost will occur immediately after exiting the Service Diagnostic mode

If the defrost heater came on in that test, that indicates your defrost thermistor and defrost heater are both good, the problem would be the main control board: W10843055

 

[bblancha]

Thanks for the reply. I had to jump the recently replaced thermostat for it to actually defrost in test 38. Does that sound right?

 

[Jake]

Sorry my bad, The defrost thermostat comes with the freezer evaporator fan motor.

Here it is for your model:
W11032800 Motor-Evap


P14-1 and P14-2 is the freezer fan motor should be 14 Volts DC --->FC fan motor output. Service Test 3, Step 2

 

[bblancha]

I can hear the fc fan running. I recently replaced the thermostat. I’m seeing heavy freezing behind the deli tray.

I measured 8.7vdc on 3 and 4. Didn’t measure 1 and 2 for FC fan.

Should I consider the FC fan failed?

It seems if I have to jump the thermostat for test 38 to work, then the thermostat is bad which is weird because I just changed it.

Thanks for help!

 

[Jake]

P14-3 and P14-4 are for the refrigerator fan motor. That should be 14 VAC as well.

But your having trouble with the freezer evaporator coil not defrosting too.

So it seems like you have two issues. So it sounds to me like your main control board is the culprit, which I posted the link to in post #2 above.

 

[bblancha]

Awesome. I’ll try that. Thank you!

 

[Jake]

Ok, sounds good.

 

[bblancha]

Replaced the control board. Freezer still not defrosting.

I measured 115vac on the brown wire at the thermostat when I forced defrost from Test 38. The other wire is orange, which should be pink according to P2-7 diagram. What’s odd to me is the orange wire is tapped from one side of the thermostat and to the heater. Should that be the other way around? If brown P2-3 is the force defrost circuit shouldn’t brown be the jump around the thermostat.

Also, it does not appear my recently replaced thermostat is closing with the coil frosted over. I can’t seem to get the board to initiate defrost without test 38.

What triggers the defrost circuit? Thermistors show working according to test 2 and 3.

Thanks for help.

 

[bblancha]

 

[bblancha]

I have heavy freezing behind the deli drawer as well. Should I consider this two separate problems? Thanks again.

 

[Jake]

What’s odd to me is the orange wire is tapped from one side of the thermostat and to the heater. Should that be the other way around? If brown P2-3 is the force defrost circuit shouldn’t brown be the jump around the thermostat.

That seems like a mistake in the tech. data sheet. Brown and Orange are the ones to the defrost thermostat.

Also, it does not appear my recently replaced thermostat is closing with the coil frosted over.

If its not closing while its frosty, then its bad.

I have heavy freezing behind the deli drawer as well. Should I consider this two separate problems?

Yes it does, make sure the refrigerator evaporator fan motor is running and the check the RC Defrost Thermistor for proper operation and placement.

I'm attaching the information about that below.

 

[bblancha]

Thanks for the reply. Would you send me the part number for the FC thermostat? I bought it from whirlpool direct and want to make sure it's correct.

The FC evap fan is running.

Also, please confirm the part number for the RC evap fan.

The RC thermistor shows good from the panel test 1 or 2 whichever.

Could you tell me what initiates the defrost circuit in normal operational mode? I connected my meter to sense 115V on brown and never activated under normal mode. This is after replacing the control board. It does however activate in test mode. The FC thermistor shows good from Test 1 or 2.

Should I change thermistors as a safe practice since I'm already in the middle of this?

Last question, PT2- 7 is a pink wire. PT2-7 shows it to be the signal to the thermostat please confirm. I will be disassembling the fridge to access the RC fan, and expect to find Pink tied to orange somewhere. PT2-5 is shown on the schematic as a bypass of the thermostat to the heater element. Can you explain the point of those two circuits?

I sincerely thank you for your help! Please send any and all part numbers you recommend changing. I don't want to dissemble again if I can help it.

 

[Jake]

Would you send me the part number for the FC thermostat? I bought it from whirlpool direct and want to make sure it's correct.

The FC defrost thermostat only comes with the freezer evaporator fan motor.

Here it is for your model:
W11032800 Motor-Evap

Also, please confirm the part number for the RC evap fan.

Here's the RC EVAP FAN MOTOR for your model:
Evaporator Fan Motor W11087438

Could you tell me what initiates the defrost circuit in normal operational mode?

The main control board does, it uses Adaptive defrost circuit per the compressor run time.

Should I change thermistors as a safe practice since I'm already in the middle of this?

The RC thermistor only comes with the RC EVAP FAN MOTOR, that's up to you, but it shows as good. You can ohm test them both per this chart I posted here:

FIXED - KitchenAid Refrigerator KRMF706ESS01, FC way too cold, RC not cold enough

Hi Guys, First, I'd like to thanks the Admins, Techs and Contributors to this forum for all the help your posts have provided in the past! We purchased our KRMF706ESS01 (s/n K730xxxx) Fridge in late-2017 after Hurricane Harvey claimed virtually all of our household appliances. Since then, it...

www.applianceblog.com

Last question, PT2- 7 is a pink wire. PT2-7 shows it to be the signal to the thermostat please confirm. I will be disassembling the fridge to access the RC fan, and expect to find Pink tied to orange somewhere. PT2-5 is shown on the schematic as a bypass of the thermostat to the heater element. Can you explain the point of those two circuits?

Here's your tech. data sheet: https://drive.google.com/file/d/1YPwMc-CyHgKzi3mqPVAEcWq_ibmzttDG/view?usp=sharing
P2-7 is the pink wire(that should be the orange wire) It may have been pink at first, then turned more orange over time, P2-3 is the brown wire that both go to the FC defrost thermostat.

Use can use a jumper wire to bypass it for testing only, or a paper clip, but don't touch the paper clip while 120 volts is going through, for bypass testing only.

FIXED - Whirlpool WRX988SIBM01 - Solving the monthly defrost ritual

Service Test - 6: Defrost Heater/Bi-metal - "bi-metal open" NOTE: If bi-metal is open, it will need to be bypassed for heater to operate. That means the Bi-Metal has to be frosty for it to CLOSE, which means continuity, and it will turn the defrost heater on. OR if its not frosty: To bypass...

www.applianceblog.com

FIXED - Whirlpool WRX988SIBM01 - Solving the monthly defrost ritual

Service Test - 6: Defrost Heater/Bi-metal - "bi-metal open" NOTE: If bi-metal is open, it will need to be bypassed for heater to operate. That means the Bi-Metal has to be frosty for it to CLOSE, which means continuity, and it will turn the defrost heater on. OR if its not frosty: To bypass...

www.applianceblog.com

You can't bypass the FC thermistor, you can ohm test it though.

 

[bblancha]

Wow! Thank you so much for all of this! I’ll keep you posted!

 

[bblancha]

Working on repairs now. I however melted/warped the plastic tray/housing that the valves and water filter components are mounted to. I placed my heat gun pointing up to defrost instead of direct heat. Too much concentrated heat. No components are damaged. Can you help with the part number? I searched the site and can’t find it.

 

[bblancha]

Defrost is working! Now the ice maker won’t seem to cycle. I performed test 57 to harvest ice. But motor won’t cycle. There are no error codes. I can force the tray to fill water with the fill test but not harvest. Help is appreciated.

 

[bblancha]

Everything is working. Found a jumped gear in the icemaker dispenser mechanical circuit.

Summary, replaced freezer thermostat, replaced control board, performed the service bulletin recommended repair on the evaporator in the fridge, and finally the icemaker as described above.

Never thought I would be chasing 4 independent problems.

Thanks for all the advice and information.