Sub zero freezer freezing up on outside back panel line causing rust and melting

SOURCE: Sub Zero Freezer Vacuum

If your freezer temps are ok, it may just be that your gasket is getting older and it becomes more porus as it ages. The vacume sound doesnt really mean alot except that the difference in the room temp and the cold of the freezer create this vacume.

SOURCE: ICE MAKER SUB ZERO REFIGERATOR

Check water turned on. check ice button switch turned on in fridge. remove juice storage, ice container in freezer, check ice bucket full white plastic flapper to make sure not stuck on a white peg at top. flapper must hang down and be freely movable to signal ice maker to keep busy. If up high will turn off ice maker. Lots of other parts especially heater circuits involved also: fill tube supply heater not working then frozen supply line then no ice. Look for wiring diagram in ziplock behind compressor grille. can order parts at repairclinic.com. logical design, layout, easy to get to sensors, heaters. makes sense if look at it long enough.

SOURCE: Sub-Zero 550 water dripping on right side of freezer forming ice on draw

I had a similar issue that started about a year ago with my Sub-Zero 550. My freezer gasket actually tore after several times of freezing closed. I thought that a new gasket would solve it, but a second but related problem developed where I was getting alot of condensation under the left side of the unit, with the water dripping onto the floor...eventually staining the hardwood floor in front of the unit.

I traced the problem to a clogged condensation drain pipe in the refrigerator. It is a corrugated pipe that drains a trough behind the crisper drawers. My pipe was clogged with black sludge and frozen down below. The condensation in the fridge would overflow out of the trough and leak below the crisper drawers, down out through the gasket.

To resolve, I used a piece of solid thin wire folded in half and twisted with a small loop at the end to fish out as much sludge as I could. Then squirted hot water into the pipe until it totally unclogged. I believe this will solve the problem without any need for a heater underneath the unit. The 550 worked fine for 4-5 years before this happened.

SOURCE: Sub-Zero 550 water dripping on right side of freezer forming ice on draw

The drain line has been clogged. There is actually a defrost heater kit for that problem if you can get the obstruction out. Did you call factory at 800-222-7820 or a local factory authorized servicer? The drain is accessed by removing the fan shroud and evaporator cover. There are a number of of phillips head screws that hold this in place. Once you have removed the two cover you will see the drain tube on the left side of the unit. I use a hair dryer to start defrosting the tube. If you have another freezer in the house it is easier just to turn the freeezer section off for a day or so. I use nitrogen to blow the line out from the bottom once everything has defrosted. Test for water flow, then put unit back together. Call the factory at the number above for the heater kit part number and they will also give you the local authorized parts supplier. The locator web address is http://subzero.com/locator/locator.aspx?type=0&zip=Zip%20Code

SOURCE: sub zero refrig - ice forming inside

The solution posted previously is TOTALLY WRONG. A Sub Zero ref doesn't have a heating element in the fresh food section. Only in the Frozen food section. It has 2 totally separate systems for each section. 2 Compressors and 2 evaporators. They share a condenser. If you are having ice build up in the refrigerator then the problem you are having is a refrigerant leak in the fresh food evaporator. You need to have a certified tech come out and replace the evaporator in your refrigerator section of your Sub Zero. Not sure what you are asking about the thermostat.