freezer temp has high swings - fridge ok

Hi,
A week ago I noticed the bread in the freezer was soft. I bought a fridge/freezer thermometer and began monitoring the temps in both the freezer and fridge compartment. The fridge seemed fine – stable in the “normal range”, however, the freezer compartment has had large swings from 0 to -20C (and a couple times I found the freezer temp just above 0). Much of the meat has freezer burn which I’ve read is indicative of these temp fluctuations in the freezer.
The seals on the freezer seem fine. This Whirlpool ET1MTMXKQ00 is about 6 years old. The compressor and fan in the freezer turn on and off normally ( that is, the every-8-hour, 21min defrost timing seems fine). I’m guessing from my perusing of all these appliance websites, is that the problem is with the Defrost system, in general, but… I’m not sure specifically what the fault could be.
I found this on the appliance411 website:
“If the defrost termination thermostat contacts short out, it will allow the defrost heater to stay on as long as the timer is in the defrost mode. A symptom of that is usually greatly fluctuating temperatures in the freezer compartment possibly causing thawing and re-freezing of food stuffs.”
This sounds like my problem. Is there a way I can test this with a multimeter? Are there any other possible ways to isolate the source of my freezer temp problem?
Any suggestions welcome!
Thanks,
Scott

Hi all,
I tested the defrost termination thermostat by unplugging the fridge, removing the cable connector plug from the thermostat and checking the resistance. While the freezer was still cool, the thermostat was closed (~0 ohms resistance), I held the thermostat in my hand and saw the state of the resistance change to infinity. I again, replugged in everything, plugged in the refrigerator, waited 10mins, and went through the same procedure. Again, the state was back to 0 ohms when it was cold. So, it seems the defrost termination thermostat is not the problem.
Some people have asked if I actually have a problem with the freezer (or am I just seeing the normal temp fluctuations due to the defrost cycle). In general, 90% of the time, the temp in the freezer is not in it’s normal range (according to my freezer thermometer). There’s only been a couple times that it’s actually been below -20C. Most often I find it’s somewhere between -15C to 0C.
Again, the fridge isn’t too old, so I’m now at a loss what the problem may be.
Any suggestions welcome (other than “get a new fridge” :wink: )
Thanks,
Scott

Hi nortonsm

If you do not see any snow on the back panel inside the freezer, most likely it’s nothing wrong with the defrost system.
The first thing I would check is the condition of the condenser coil, located under the fridge (#3 on the unit break down diagram). If it’s blocked with lint, the compressor is overheated and not performing properly. Cleaning the condenser will solve the problem.

  • For the future references here are the break down diagram for the Whirlpool refrigerator Model ET1MTMXKQ00

Good luck.
Gene.

I agree with Gene, very rare a termination thermostat suddenly opens well above 50 degrees.

Gene,
I think you’re right! I had stupidly assumed that the condenser coils were behind the difficult-to-remove back panel (I had removed the easy-to-remove lower back panel to view the compressor, etc) and had never removed the bottom front panel giving way to the VERY CLOGGED condenser coils.
I vacuumed them and already notice improvement. I ordered a condenser brush to further clean them – I was also wondering about using a can of compressed air along with the vacuum – the back portion of the coils seem quite difficult to reach (there’s a panel that blocks accessibility to the back of the coils from the lower back side of the fridge).
Thanks again for the suggestion!
Best,
Scott

Hi all,
I’ve had quite an adventure tracking this problem down… and I think I’m close but need a little advice to finalize the issue.
I’ve included a JPEG attachment which shows a graph of my freezer temperature over the period of about 2-3 days (I have a temperature logger I can put in the freezer which logs the temps and which I can later download to computer). Notice the sawtooth behavior where I get peaks up to around 20F and dips down to about -3F. The intial peaks in temperature are spaced around 18hours and the last two peaks are only about 8 hours apart.
When I first noticed the freezer was getting warmer than it should, I cleaned the condenser as per the advice in this thread. Indeed, it was quite dusty down there and I cleaned it the best I could given the limited access one has with this Whirlpool refrigerator. Still, I see the temperature swings…
Then, I pulled out the clamp ammeter and line splitter and checked the current draw from the compressor. It was then that I noticed I was hearing little clicks from the compressor area… Checking the current draw I saw the current at 0.2A and then after a click, the current jumps to 7A but immediately falls back to 0.2A…it continues to repeat this cycle over and over every few seconds. I believe this is happening in the upward swing in temperature of the sawtooth temperature curve (i.e. the compressor isn’t able to start up). Later, after going out to dinner and coming back and checking the current draw, I saw it was now stable at 1A and the temp in the freezer was about 3F and I think heading back toward 0F.
I’m now considering that it’s the starter relay, but … I can’t figure out why the compressor is able to eventually start up. Is it not the starter relay and instead overheating? Could the starter relay cause this issue? I have yet to go through the website diagnostics on testing the starter relay, but plan to soon. However, I thought I would check with the forum to see if anyone can use the info above to tell me exactly what the issue might be.
Thanks!!
-Scott
FreezerTemperatureLog.jpg (18.3 KB)

Now your compressor is a hard starting unit. Best to order the factory specified start relay and install. If this doesn’t fix the problem, you have a bad compressor.

Now your compressor is a hard starting unit. Best to order the factory specified start relay and install. If this doesn’t fix the problem, you have a bad compressor. That part # is AP3961332

:)Whirlpool S/S Refrigerator #ED20TKXFW00 1/1999

I’m having the same kind of problem as Scott with the freezer compartment having a daily warming cycle up to 20-25 deg then back down again to 0 deg. The coils are cleaned annually and I’ve never had any ice buildup in the freezer. I recently replaced the defrost timer and the t-stat. Do you think this might be a problem with the start relay? And how do you get that plastic cover off the start relay connections?

Thanks

Mark G

giaconsultants,

Did you see the same situation with the compressor as described by Scott?

Gene.

Clean the condensor coils under the refrigerator with a coil brush,there are usually two knobs with numbers in the refrigerator compartment,the one to the right is the thermostat,turn that to number 5 the one on the left control a shutter that let different amouts of cold air into the refrigerator,turn it to number 2,the lower the number the more air will be allowed into the refrigerator,wait 24 hours for the temperature to stabilize,after 24 hours if the temperature is not perfect in the refrigerator and the freezer check to make sure both evaporator and condensor fan motors are working ok,if they are both working ok the problem is a weak compressor.

Fyxer - Hot Hubs

Whirlpool, S/S Refrigerator, #ED20TKXFW00, 1/1999, no ice maker, no water

Gene,

It’s not exactly the same problem as Scott’s his freezer compartment had a daily warming cycle up to 20-25 deg then back down again to 0 deg. Mine is a spike that mostly effects ice cream or ice.

The freezer and refrigerator both are consistently cold. The freezer temp spikes to 20-25 deg, but the average temp stays near 0 deg. The spike seems to coordinate with the defrost cycles.

The t-stat is set midway between off and #1, the freezer damper is set to coldest. Freezer averages 0 deg and the refrig averages 30 deg.

I just replaced the T-stat (whirlpool part) because it sometimes would not restart without a gentle tamp and replaced the defrost timer (whirlpool part) just because I was inside the control cabinet.

I clean the coils, compressor and fans annually and I’ve never had any ice buildup in the freezer. The water tray under the freezer is always dry.

I wondered if the freezer temp spike is related to the defrost cycle? And am clueless about why the t-stat setting doesn’t seem to be calibrated to the temperature? :confused:

Thanks

Mark G

Hi Mark,

Looks like you were right and the first failure I suspect must be the defrost thermostat (#35 on the unit break down diagram). If it stays closed during the full defrost cycle (which it’s not supposed to) the defrost heater stays “on” to cause excessive heat in the freezer.

Here are the break down diagrams for the Whirlpool refrigerator Model ED20TKXFW00

Gene.

Whirlpool, S/S Refrigerator, #ED20TKXFW00, 1/1999, (no ice maker or water dispenser)

Gene,

Since I just replaced the timer and t-stat, I’m going to observe the freezer and refrig temp conditions for the next few days and then do an update.

Thanks

Mark G