Freezer too warm - thermostat or leak?

Question

Frigidaire FRS26LR5CW0 side by side fridge/freezer. Freezer side is cool, but not cold - things were slowly thawing and new stuff not freezing so I had to remove everything. Fridge side is just cool enough to keep the food in it.

What I've done/checked:

• Cleaned exterior front/back coils/compressor/kick plate.
• Verified the exterior compressor fan works--Compressor comes on (i can hear it)
• I removed interior back panel of freezer - the fan above the coils works, as well as the fan that blows from freezer into fridge (located on left rear Fridge wall).
• When i first opened the back up, the freezer coils were frozen, but only the top 1-2 rows. I believe the inlet line is the small diamater line - that line had a big block of ice formed on it, probably an inch thick.
• I've defrosted and re-started and the inlet line (the small diameter) almost immediately frosts up, and within a couple of hours the first row is frosted up. I let it run for 4 days and got another block of ice on the inlet line.

One strange thing i noticed - there was some kind of black tape/putty that was apparently on the inlet/small line that looked like it had melted and oozed down onto the coils. not sure what it's purpose was...?

I also looked at defroster - this model has adaptive defrost control. I found out how to trigger it with the door light switch. When I do, the compressor & fans turn off. I disconnected the defroster element and checked the connectors - they showed 114VAC, so looks like it's getting power. I also checked the two ends of the elements w/ohm meter and it read zero ohms, so it would appear intact.

My questions:

1. Could the thermostat (small plastic thing that clips to the freezer coils) be defective causing the compressor not to run long enough? It does cycle off, which seems strange since it's so warm.
2. Is there a way i can test it, or bypass it to force compressor to run continuously for a while to see if that resolves the problem?
3. I've read a lot online about all the coils freezing up, and blocking air flow/heat transfer - but why only top 1 or 2 rows freezing up?
4. I think the defroster was a red hearing (seems it could be the culprit if all the coils were freezing solid) but i'm curious how hot it should get as when i forced it on, it didn't seem to get warm at all

Thanks for your assistance, Mike

Answer 1

Sounds like you're low on refrigerant. The sealed loop internal pressure has dropped low enough that all the evaporation is happening in the top two layers of the evaporator coil.

You could replace the refrigerant, but the question will remain: what caused the loss? I suggest that a qualified ($$, I know) repairman is your best chance at finding and repairing the leak.

Answer 2

I have found on newer units with R134a once they overheat the system needs pulled to a vacuum with the freon recovered and recharged with fresh R134A. This will cost a bit but is cheaper than a new fridge. I don't do many small units like this but have seen it 2X on a fridge where a mouse was stuck in the fan, and another with horrible dust buildup that stopped the fan. You really need someone with a 608 type 1 license (the lowest level). The fridge will have less than 5 lbs freon and probably closer to 1Lb. There should be a tag that tells the type of freon and the quantity.