Whirlpool Top Mount Freezer not maintaining temperature

Refrigerator & Freezer Repair
1

I have a 5 year old Whirlpool refrigerator with top-mount freezer. Several time over the last month I’ve taken items out of the freezer only to find them partially thawed. I put a temperature logger in the freezer for several days and see that the freezer chills to ~0°F and then warms up to ~20°F. The warm ups don’t appear to be the defrost cycle. Those appear to be occurring as well (based on sharp sudden spikes in the chart). This is a more gradual, several hour increase. I’ve troubleshooted a number of things and am not certain on my next step. Let me run through what I’ve checked so far:

  1. Checked freezer coils during operation - didn’t seem like there was excessive frost, but may have been based on when in the temperature curve I had pulled the cover off.
  2. Defrost thermostat - checked continuity under warm and cold conditions. Appears to be working properly.
  3. Defrost heater - Continuity check seemed to indicate it was working. Also, brief sharp spikes in the temperature profile seem to indicate this is working as well.
  4. Fan in freezer - operates normally
  5. Coils under the fridge - These were a mess. I vacuumed and cleaned as best I could. They’re not very accessible. Look much better, but certainly not like new. This cleaning appeared to make no difference in operation.
  6. Freezer temp control flap - Not broken or stuck. It seems to me, based on anecdotal evidence only, that turning the freezer colder makes the problem worse. In the least, it doesn’t make it any better.
  7. Compressor and fan - The fan runs when the compressor is running. The compressor turns on and doesn’t make any odd noises when running. That being said, it seems to me like the compressor goes for very long periods of time before turning back on. I’ve found that turning the fridge to a colder setting, and then putting it back to it’s normal setting (3) kicks the compressor on. Then the refrigerator operates normally for a few hours until the refrigerator reaches temperatures, the compressor kicks off, and then sits idle for a long period of time allowing everything to warm up.
  8. Freezer door seals - As best I can tell, these are in good shape and performing normally.

I’m at a bit of a loss as to what could be the problem. The only two things I can think may be the problem is that the refrigerator thermostat is sticking/failing or the ADC control board is messed up. I’ve reset the board several times, but I’m not seeing any real improvement (maybe briefly, but it’s hard to tell). I’m thinking it’s not the compressor or refrigerant being low since it’s able to cool fine when it’s actually running.

Any suggestions? My next step is to just buy a bunch of parts and start swapping them out in hopes one of them is the culprit.

2

Here are your parts
Parts for Whirlpool ET1CHEXVB01 Refrigerator - AppliancePartsPros.com

Based on your diagnosis procedure which by the way is exceptional I would replace the control thermostat. It is not uncommon for theses to stick in the open position.

Your general description points to a bad thermostat and " I’ve found that turning the fridge to a colder setting, and then putting it back to it’s normal setting (3) kicks the compressor on." adds more to my feeling this is the correct part.

3

Thanks, denman! I was leaning toward this as this morning I had tried another experiment. In previous cases, briefly turning the thermostat cooler kicked the compressor on. This morning, when I observed melted items in my freezer, I turned the refrigerator thermostat WARMER and the compressor kicked on. This further bolstered my belief that the thermostat was sticking and not telling the compressor that it was too warm in the refrigerator. I’m going to order the replacement part and see how it responds. Thanks again!

4

I just wanted to pop back on and post what the solution to my problem was, in case it benefits others. I especially wanted to do this because most threads I found related to my problem indicated a faulty ADC board, defrost thermistor, or dirty coils and few actually posted the solution once they resolved their problem.

None of these components turned out to be a problem for me. Instead, as denman had confirmed previously, it was my refrigerator thermostat that was causing tons of issues with my freezer. The thermostat was sticking and not telling the compressor that the refrigerator had warmed to a point that it should turn on. The problem was intermittent, so occasionally it would cool just fine, other times the refrigerator/freezer warmed to near room temperature. I purchased a replacement thermostat and installed it last Saturday (now Tuesday). The refrigerator has been as good as new (especially since I cleaned the coils during the troubleshooting phase). Hope this helps others!