LG LMX25964 not cold enough? Here's how to fix it!

A previous commenter noted that his LG LMX25964 wouldn't get cold enough. He said that he'd set it at 33F (the minimum) and it wouldn't get below 38F. I had the same problem, except mine wouldn't get below 39F when set at 33F. The freezer was set at the recommended 0F and worked fine.


After complaining to LG about this, LG sent a tech 4 times to replace various parts (baffles, temp sensor, main board, etc.) but after no luck I told Best Buy that I wanted an exchange (I was still within their 30-day return policy) and they got me a new fridge. No hassle, no charge.

When the new fridge was delivered, the problem was the same and it wouldn't get below 39F when set at 33F. Note that the accuracy of my thermometer was verified by immersing it in ice water which should have a temp of exactly 32F.

  • Tip: The air temp varies inside a fridge depending on whether the fan is on or not, the best way to check the temp is to stick a digital thermometer inside of a glass of water that has been in the fridge for a few hours. The glass of water won't change temp when the fridge fan cycles on and off.


Anyway, back to the main topic... LG sent their tech again who verified the same problem with the new fridge. Fortunately, I had a good tech and he was as confused by this problem as I was. He got on the phone with his LG contacts and insisted that there must be an adjustment.

The first support person
didn't know of an adjustment but he eventually spoke with a more experienced support person. Eventually, he found out that there are some jumper wires on the main board that can be clipped to adjust the temp.

Clipping jumbers 1 and 2 should *increase* the fridge temp by 3 degrees while clipping jumpers 3 and 4 should *decrease* the fridge temp by 3 degrees.

The tech unplugged the fridge, located the jumper wires on the main board and clipped wires 3 and 4. After 24 hours my fridge was down to 35F (4 degrees lower than before). This was all it took to fix the problem.

My interpretation of this is that the factory calibration settings for the temp sensor in this fridge result in a temp that is about 6F on the high side of the setpoint. I observed this same behavior on 3 different main boards on 2 different fridges.

I can't say for sure, but maybe having the temp running a few degrees on the warm side could be a way to achieve a lower energy consumption for those yellow stickers (Energy Star) that are on the inside of all of the fridges at the store, who knows...

Anyway, I'm sure that this fix would have solved the initial problem had the tech known about this jumper setting. Not only did the tech not know, but even his first level support person answering the phone didn't know either and it took a total of 5 trips and a new fridge to figure it out.

It still doesn't reach 33F but 35F is good enough for me.

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Comments for LG LMX25964 not cold enough? Here's how to fix it!

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Jul 28, 2022
I have LFXS28596S with exact same problem NEW
by: Anonymous

Where is the circuit board located?

May 24, 2022
LG REFRIDGERATOR NEW
by: RANDY

I HAVE MODEL LRMD23063 FRENCH DOOR WILL NOT COOL DOWN BELOW 40 WHERE ARE THESE WIRES

Apr 23, 2022
Still investigating NEW
by: Anonymous

Looks like page 20 of this LG service manual details the jumpers and which you can cut to get the desired undercool setting engaged.

https://research.encompass.com/ZEN/sm/LRSES2706V.pdf


Cutting 3 and 4 will lower the internal temp target by 2 degrees


Apr 23, 2022
Still investigating NEW
by: Anonymous

Upon doing some searching and reviewing LG boards, the "control board" seems to commonly have four exposed circuits (small metal wires exposed for cutting)

The one I've seen has them labeled JCR1-4 - and the circuit board itself says that 1-2 will lower a degree (Celsius) each and 3-4 will raise a degree.

They can be seen here, just by the barcode.

https://www.partsimple.com/lg-ebr41956426-refrigerator-control-board.html?gclid=CjwKCAjwx46TBhBhEiwArA_DjKkNDoVmffqZeOol4KuTgzQPV9sk-Ut6lycmYkVBi9OHPTrNXrFKTBoC8NUQAvD_BwE



If 3-4 truly will lower temps in the fridge, then that means you're skewing the thermostat temp sensor up 2-3 degrees which tells the fridge to run the compressor for longer.

Apr 20, 2022
LUPXC2386N model but same warm fridge problem NEW
by: Anonymous

I have the LUPXC2386N model but the same problem with the refrigerator being 5 degrees warmer that the set temperature. I have downloaded the manual and the parts list and diagrams but there's no mention of the word "jumper" anywhere. I'm very frustrated at this point and will never purchase an LG product again. Very disappointed in them.

Apr 02, 2022
Location of the main circuit board? NEW
by: Anonymous

We have the very same frig, and from New was never cold enough. Will do some more research on the location. May bbq e I will attempt to clip those two wires myself. That energy star qualification is achieved by false interpretation of cooling food temperatures. We have to watch our milk by the day so not to consume spoiled milk and meats.

Mar 29, 2022
Thats what the manual says NEW
by: Anonymous

The manual does note the jumpers to change refrigerator temp.

Mar 13, 2022
Clip jumper wires 3 & 4 to lower fridge temp 5 degrees NEW
by: Hillsborough

Yeah, I don't think the guy who originally posted the solution to clip jumper wires 3 & 4 to lower the fridge temp by 5 degrees is notified of any comment updates on here so I don't think we'll ever hear back. I downloaded the schematics for my same fridge but don't see anywhere that says wires 3 & 4. I'm ready to start my google search all over again and see if there's anything new out there.
Kind of ridiculous that LG allows a +/- 5 degree temp variation in fridge after people pay all this money for them. I'm definitey not buying LG brand again.

Mar 13, 2022
more detail
by: Frustrated

A great hack to cut/clip jumpers..to cool LG .where are the wires specifically located. Need more detail.

Aug 17, 2021
LG Temperature Problem Solved (for me) NEW
by: larrymcj

I just purchased a new LG refrigerator and found this thread thinking I had the same problem...not cold enough. I purchased an expensive, commercial food storage thermometer and also a VERY expensive instant-read food thermometer and started testing.

What I found out is if my refrigerator is set for the recommended 37 degrees, the circulating air inside the refrigerator is only 41-42 degrees. After paying $3600 for this refrigerator I was almost ready to return it.

Something made me purchase the very accurate and expensive instant-read food thermometer and test the actual items in the refrigerator instead of the air. Milk-37, pickles-37, soda-37, cottage cheese-37. By now you're getting the picture. EVERYTHING in my refrigerator was exactly 37 degrees (the configured temperature) even though the air inside was 5-6 degrees warmer.

I'm guessing a vast majority of the temperature complaints about LG (and other) refrigerators are unfounded and the units work fine...but the air measures incorrectly. Probably something to do with moving air measures less than it cools...I'm not educated in that area so I don't have a clue. But I do know these thermometers I used were both certified to be accurate to less than one degree so I'm believing what I see.

Jul 13, 2021
How / where to clip jumper wires 3 & 4?
by: Anonymous

I have the exact same problem with my new LG refrigerator. The only difference is it used to get the fridge down to 33 I believe, but now only around 40 even though I still have it set at 33. When you say clip jumper wires 3 and 4 do you mean just cut them? Or something different? I’ll try looking at my Manila to see if I can locate jumpers 3 and 4.

Thanks!!!!

Jun 02, 2021
Blocked Airflow Duct From Freezer To Fridge Side NEW
by: QAStickerShock

In our case, the fridge side of the unit was not getting cold and stayed at 58 degrees Fahrenheit because some knucklehead at the factory had stuck a 5.5" x 4" Quality Assurance sticker over the air duct from the freezer side to the fridge side of this side-by-side, Model LSXC22426S/07. The LG repair technician had to remove the water filter assembly and then the vent assembly at the top of the fridge to be able to remove the 'Quality Assurance' sticker. After removal of the blockage, the fridge cooled down to the desired temperature (35 F) within about 45 minutes.

May 17, 2019
Same problem NEW
by: Brew

I have the same problem with my new LG fridge. I am hoping to find a fix like this for my fridge too.

Feb 21, 2018
Same Problem NEW
by: Mitch

I have a 2 year old LG 3 drawer model that is doing the same thing. I had the fan, compressor/dryer replaced, but top fridg never maintains the 33 degree thermostat setting. I notice wide temperature swings. At times my cup of water is 35 degrees, then later its 42 degrees. The air temp in fridg can occasionally show 35, but most times it's 38 to 44, all while thermostat is set to 33. How hard is it to jump the wires described? Are there any photos that show the location? What exactly do I do to jump the connections. Thanks

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