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Ditch or not, LG LFX28978ST sometimes cools, sometimes doesn't

toasty

Member
Joined
Sep 22, 2018
Messages
1
Location
OH
Model Number
LFX28978ST
Brand
LG
Age
6-10 years
A couple weeks ago my LG LFX28978ST stopped making ice. Frig temps were ok, freezer was slightly elevated - about 5-10 degrees. This went slowly downhill over three days though. Eventually the temps in the freezer got to around 30 and the frig was about 45. I checked the circuit board and there was a LED light that blinked with a 2 on, 1 off pattern.
lg-pcb.jpg

The condenser coils were not excessively dirty but we blew some dust off them.
lg-coils.jpglg-comp.jpg

I had a tech come out and he checked the evaporator in the freezer, said it was likely and sealed system problem, but that they don't work on those issues with this brand. Fortunately he didn't charge me.

Now I left the LG running over the next few days and surprisingly the temps came back down. The frig got down to 38-40 within a day. The freezer took longer but also got to under zero. I had the temp set to -6 and it seemed to make that. It even resumed making ice - enough to fill the bucket and then some. It fluctuated but held its temps for a few days. Then the freezer temps started to rise again, only to about 20. I finally got a chance to open the freezer myself. It took me a little while to figure out how to get the back off to see the evaporator and by the time I did most of the frost had melted.
lg-evap1.jpg

I closed it up but left the back undone a bit so I could take a look after it had a chance to cool down again. When I did, the frost seemed to be mostly along the upper two-thirds. And right before this the temps had been close to zero.
lg-evap2.jpglg-evap3.jpg

The compressor was extremely hot at this time (around 130) but that may be because I had the back panel off the whole time. It has cooled down since I put the back panel back on, but was still very warm to the touch. The freezer is now taking a long time to cool off though, only dropping to the mid 20s after several hours. Also, all the fans are running. Especially the evap fan, accidentally cut my finger on it, it was running so well.

So is this likely a sealed system problem? Could it be a problem with the PCB, or capacitor on the compressor? I can probable replace the PCB myself, having a computer background, but probably not the refrigerant parts. Knowing the reputation of this brand (now anyway), is it worth trying to fix it - assuming I can find someone who will? The frig is otherwise in good shape. Only the compressor is still under warranty, but that does seem to be doing it's job, at least sometimes.

I really appreciate any helpful insight on this. I'm happy to provide more detail if I've skipped over something important. Thank you!
 
Last edited:

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
106,343
Location
McMullen Valley, Arizona
Hi,

You have a sealed system problem.

The sealed system consists of the compressor, condenser, evaporator, heat exchanger, filter/drier and refrigerant. Common problems with a sealed system are bad compressors, refrigerant leaks, and system restrictions. Sealed system repair costs will often exceed the machines value.

You will need a LG tech to come out to determine if its your compressor, you do have warranty on that.

Usually if the compressor is super hot, that's a sign of a failed compressor.

Jake
 
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