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FIXED Whirlpool WRX988SIBM01 - Solving the monthly defrost ritual

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tvstrategies

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Model Number
WRX988SIBM01
Brand
Whirlpool
Age
1-5 years
Hi - The evaporator in my fridge keeps icing up. Please help!

Thanks
- Steve

Summary: I'm trying to verify that I understand what the fridge diagnostics are telling me, and then, what steps to take for repair.

Details: About once a month, like clockwork, "something" (fans? compressor?) inside my fridge spin up to roughly the volume of a Boeing B-17 and the freezer begins to warm up. The first time, a technician dismantled and removed the freezer drawer, and showed me that the evaporator was completely encased with ice. A day later, after it melted, he came back and replaced a small cube-shaped device that he called the thermostat. At the time, he told me that the only other thing that could go wrong would be the heating element.

A month later, the problem recurred; so I defrosted, removed the drawer myself, and replaced the heating element that surrounds the evaporator, which is item 10 on this page:
This did not fix the problem. But instead of another $200 technician visit (or roughly the monthly cost of a Whirlpool "appliance insurance policy"), we have learned to tolerate defrosting the fridge on about the 15th of each month.

Finally I became sufficiently weary of this that I called a different repairman. He told me that while he had not been trained on this model ("because it has two control boards - a master plus one that runs the relays"), BUT - that I should look for the Tech Sheet, and run the diagnostics - which should help. Which I found here: https://drive.google.com/file/d/1OYqSdcvclakDM1Tmwy9MIAdseXvJzrmh/view?usp=sharing

I successfully made it through the first five service tests: Test 1 (pass=01), Test 2 (pass 01), Test 3 (both fans work), Test 4 (all the modes seem to cycle through ok, and there's air flow through the main compartment, the "pantry" drawer, and the freezer), Test 5 (the compressor cycles from min to max to min).

Which brought me to Test 6, the Defrost Heater/Bi-Metal. Which brings me to you. I found a thread between Jake and a frustrated fridge owner . In my own case, Test #6 resulted in "02 = bi-metal open." Jake quotes the Tech Sheet as saying "if the bi metal is open, it will need to be bypassed for the heater to operate." https://www.applianceblog.com/mainf...of-freezer-frosting-up-food-is-thawing.77989/

So, before I go any further, can this situation be resolved by using the diagnostics routines listed on the Tech Sheet, to test and change settings?

1) Can I "bypass the bi-metal" by going to one of the test routines and using the controls on the front of the fridge to fix my problem? (And, what is the "bi-metal" - the name of the heating element or the thermostat?)
2) If so, where are the instructions to bypass the bi-metal? (please reply with URL or step-by-step)
3) Or, will changing the Defrost Mode (in Test 7) help? I'm not sure what this is telling me - that I can set the fridge to defrost automatically if the compressor is running continuously for more than 8 hours? (And would the cake of ice around the evaporator eventually melt?)
4) Or, do I have to force-defrost (Test 38) every month, forever? (And how do I exit Test 38? by unplugging the fridge?)

Or... do I need to replace one or both of the control boards? Is there a pass/fail diagnostic for the boards? Can you direct me to those instructions or reply with step-by-step? I don't have a multimeter but can buy a basic one and learn.

Or if I have strayed completely off base, what's your advice?

Thank you THANK YOU!!!
- Steve

PS - Can you please verify that I have the right diagram here?
I see that the control boards are accessible from the rear of the fridge - Item 2 and Item 5.
WRX988SIBM01.jpg

PPS - I am totally not a fan of the design of this refrigerator - how can ANYONE design a fridge with a meltwater tray that 1) has a capacity of less than an ice-encrusted evaporator coil so your nice hardwood floor gets ruined, and 2) doesn't slide out (not removeable) - you have to get on the floor, remove the plastic fascia, snake a tube in there and siphon the darn thing!
 
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Jake

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Ok Steve, I'm confused. You said this--->Hi - The evaporator in my fridge keeps icing up. Please help! Then you said this--->Details: About once a month, like clockwork, "something" (fans? compressor?) inside my fridge spin up to roughly the volume of a Boeing B-17 and the freezer begins to warm up. The first time, a technician dismantled and removed the freezer drawer, and showed me that the evaporator was completely encased with ice. A day later, after it melted, he came back and replaced a small cube-shaped device that he called the thermostat. At the time, he told me that the only other thing that could go wrong would be the heating element.

Which evaporator coil is icing up? The FREEZER compartment coil or the REFRIGERATOR compartment coil?

That defrost heater is ONLY used for the freezer evaporator coil.:)

The refrigerator side evaporator does NOT use a defrost heater, it uses a FAN and thermistor and a 3-way solenoid from the sealed system to defrost that refrigerator evaporator coil.

There is a service bulletin on this issue, but I need the serial number of your refrigerator to see if it applies to yours.

Jake
 

tvstrategies

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Hi Jake, Thanks for the quick reply. I was referring to the one that's exposed at the rear/bottom of the refrigerator, after the freezer drawer is removed (which I assumed was the freezer evaporator).

It is item #20 in this diagram:

Refrigerator's serial number of the fridge is: K53909012
 

Jake

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tvstrategies

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Hi Jake - Are you saying that the freezer drawer seal may be faulty - and that this has nothing to do with a control board or other electronics failure? Not the answer I expected!

You directed me to a Technical Service Pointer, which says "It is possible that consumers may experience frost, or hard ice, forming on the front area of the freezer compartment" - but that's not the problem I'm experiencing. There is no ice or frost within the freezer compartment. It's the evaporator coil, which is behind a separator between the back of the refrigerator and the freezer compartment.

Lingering questions...

1) If I were to call Whirlpool or a Whirlpool authorized repair provider, would this situation be considered as a product defect, eligible for a free Adaptor Kit and installation labor?

2) Also, my initial questions, in case this problem persists even if I install the Adaptor Kit - Can the recurring evaporator coil freezeup be resolved by using the diagnostics routines listed on the Tech Sheet, to test and change settings?

- a) In Diagnostic Test 6, where it says I can bypass the bi-metal, how is this done? Are there instructions for that? (please reply with URL or step-by-step) Is it one of the test routines where I can use the controls on the front of the fridge? (And, is the "bi-metal" the name of the heating element or the thermostat?)

- b) Would changing the Defrost Mode (in Test 7) help? I'm not sure what this is telling me - that I can set the fridge to defrost automatically if the compressor is running continuously for more than 8 hours? (And would the cake of ice around the evaporator eventually melt?)

- c) Or, do I have to force-defrost (Test 38) every time the freeze-up recurs? (And how do I exit Test 38? by unplugging the fridge?)

Also, is there a pass/fail diagnostic for the control boards? Can you direct me to those instructions or reply with step-by-step? I don't have a multimeter but can buy a basic one and learn.

THANK YOU!!!
 

Jake

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Ok, got it!

I thought you meant frost was forming on the front cover of your freezer evaporator coil.

Jake
 

Jake

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Ok, lets start over and lets keep it very simple, let's ALSO forget the TEST 6, it's too confusing what they say.

You have already replaced the heating element, so that part is good. The only 2 other parts left in the auto defrost circuit is the defrost thermostat and control board.

Its possibly the defrost thermostat, it ONLY comes with the evaporator fan motor. The defrost thermostat is the black circular part that clips to the top of your evaporator coil.

--->The way to test the defrost thermostat is to unplug the refrigerator from the wall outlet, then pull that plastic electrical connector out that it goes to, it unsnaps, then use your multimeter and set it on 200 ohms and ohm test the defrost thermostat WHILE ITS FROSTY, if it's not frosty you will not get a proper reading. If your meter doesn't change numbers while your ohm testing it, then its bad. It should read 0 ohms WHILE FROSTY.:)

The wires you will need to ohm test from that electrical connector are the orange and brown ones.

Here's the defrost thermostat and evaporator fan motor for your model:
W11032800 Motor-Evap


Jake
 

tvstrategies

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Outstanding - thank you. Since the fridge was defrosted, I'll need to wait until the problem recurs in a few weeks.

Meantime, I'll go buy a multimeter and when it freezes up again, test per your instructions.

I'll let you know how it turned out, for benefit of anyone who finds this thread in the future.

If solved, I'll post a message that says so.

Best regards,
- Steve
 

Jake

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Ok, sounds good, yes keep us posted.

Jake
 

tvstrategies

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Hi Jake, Well, my fridge has iced up again. Just to make sure I understand your instructions... I'm buying a multimeter now.

Here's the defrost thermostat and evaporator fan motor for your model
W11032800 Motor-Evap

1) On the parts listing that you sent to me, the wiring goes to a white molex connector. So, I apply one probe to the metal contact that terminates the brown wire inside of the connector, and the other to the contact for the orange wire inside of the connector? I don't need to expose the actual conductor from the insulation of the wire itself, right?

2) The diagram to the left to the 5 pictures in the parts listing says that this is item 13 in the diagram. It's not clear to me where it is. Is it behind the flat panel (item 4) at the back of the freezer compartment, and easily accessible once that panel #4 is removed?

Then I'll give it a try and confirm whether or not it has failed (reading of zero ohms)

Thank you!
- Steve
 
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Jake

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Yes Steve, unplug that big huge plastic molex connector on the left side, then the wires you will need to ohm test from that electrical connector are the orange and brown ones, the defrost thermostat has to be frosty to get a good reading.

It should read 0 ohms while its frosty.

2) The diagram to the left to the 5 pictures in the parts listing says that this is item 13 in the diagram. It's not clear to me where it is. Is it behind the flat panel (item 4) at the back of the freezer compartment, and easily accessible once that panel #4 is removed?
I'm not sure what you mean, post the link to the diagram you are referring to.

Jake
 

tvstrategies

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Hi Jake, With the fridge unplugged, I removed the drawers, back panel, and wiring harness assembly, and did the measurement. Below are the results. Based on the result (at the end), I'm not sure if the thermostat passed or if it has failed.

Before I forget to ask, do you have (or can you point me to) a PDF of the service & repair manual for this fridge (Whirlpool WRX988SIBM01). Not the user manual, tech sheet or installation manual. The actual service manual. I can't find it online. I already have the others.

Thanks
- Steve

Here is my test process -

(Pic 1) I could not access the thermostat (the flat circular device clipped to copper tube) without clearing away the frost first, so instead, I detached the entire thermostat/fanmotor/harness assembly and immersed the thermostat about 3" down into slush and cold water and let it sit for a few minutes before taking the electrical measurement. The best temp I could get was about 35°f.
1-fridge-thermostat-immersed.JPG


(Pic 2) I then inserted the multimeter's red and black probes into the molex connector, at the positions of the brown and orange leads, so that the probes were in contact with their respective metal contacts inside the molex connector.
2-Fridge-probes-on-molex.JPG


(Pic3) With the multimeter set to 200 Ω, the reading is '1' followed by a few spaces, and then a decimal point. This reading did not fluctuate or change. I also reversed them (black/red probes to brown/orange contacts, and then red/black probes to brown/orange contacts) but that made no difference.
3-fridge-resistance.JPG


If I understood you correctly, this means that the thermostat has failed and the wiring harness assembly with the thermostat and fan motor must be replaced - please confirm. Thank you!
 
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Jake

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Did the meter change from 0 to 1 when you tested it?

Touch your meter probes together and tell me what it reads.

Jake
 

Jake

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Ok Steve, that means the defrost thermostat is bad, because you should of got 0.6 while the defrost thermostat was in the ice water.

So yes order the new defrost thermostat that comes with the evaporator fan motor in post #7 and you should be good to go.:)

Jake
 

Jake

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Yes, that's it, order it.:)

Yes, keep us posted.

Jake
 

tvstrategies

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Hi - Part purchased, installed, and fridge is running! Interior is cold. Freezer is working. Hopefully, problem resolved!

Thanks again for all your help.

Best regards,
Steve
 

Jake

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Excellent Steve, glad to hear that.(y)

Thanks for the update!

Jake
 

tvstrategies

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Hi Jake,

I'm back! After a quiet 45 days or so, the fridge is back in the same mode: the fan is racing constantly. The compartment that contains the evaporator is a solid brick of frost. I had replaced the defrost thermostat and associated wiring harness (as above, in this thread). Previous to that, I had also replaced the heater loop, see item 10 in this diagram:

What do you suggest I try next? Replace the control board (which one)? My first thought was to do a factory reset of the refrigerator, but the Tech Sheet doesn't have this information.

This is a three year old, twenty five hundred dollar refrigerator. I no longer trust the "professional help" that make house calls in my area - they all cost dearly and have let me down every time. Gotta love it.

Thank you
Best regards,
- Steve


Further details, in case it is helpful:

If you look at the Tech Sheet for this model: https://drive.google.com/file/d/1OYqSdcvclakDM1Tmwy9MIAdseXvJzrmh/view?usp=sharing

Service Test - 1: FC Thermistor - this test passes, so the thermistor is working?
■ The board will check the resistance value of the thermistor and display flashes results on the Temp display (01 = pass, 02 = open, 03 = short).

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.
I have no idea what this means - Does it mean that the heater element is not on? How do I "bypass it for the 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).

Service Test - 38: Forced Defrost Mode - I have set it to Long 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.

Just now, in case it makes a difference, I tried to set Forced Defrost Mode to Long Defrost. I have no idea if my selection of LO actually 'took' when I exited diagnostics mode. The fan is still whirring away. When I re-entered diagnostics mode and looked, Test 38 said OF again.
 
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