Subzero 700TC Freezer not cold enough; bottom drawer warmer than top

[drobins9]

Hello- I have two side-by-side Subzero 700TC units that each have a refrigerator on top, and two freezer drawers in the bottom.  In one of them, the freezers are not getting cold enough.  Here are some notes:

• I cleaned the evaporators, which were dusty in both units, but no effect.
• There is generally more heat and more fan noise (although not an unusual amount) coming out of the unit that fully works properly.
• In the unit not working properly, the bottom freezer drawer is 20 degrees, and the top freezer drawer is 10 degrees, whether I have the freezer set to 0 degrees or -10 degrees.
• The refrigerator is cooling perfectly and is the 38 degrees it is set and and that it is reading.
• One other odd thing, the control panel often says the freezer is between 1 degrees and 3 degrees, when it is really about 10 degrees in one drawer, and 20 degrees in the other.  Since I set it for -10 degrees, I don' t think that is impacting its (in)ability to cool properly, though.

There is no ice on the evaporator or in the workings.  I am trying to figure out what the issue is.  I hear a fan running, but not quite as loud.  With the lower level of heat coming out of the bottom, I am wondering if the fan is not as effective as it should be.  Although, I suppose if the compressor isn't fully doing it's job, that could cause less heat, too.  I think the lower drawer being 10 degrees less than the upper drawer is probably a clue to what is going on.

Any suggestions?  Thank you!

[Slav]

No frost on the freezer evaporator and low heat coming from the condenser coils indicate a some sort of Sealed System problem... leak, restriction, inefficient (bad) compressor. The next step would be to install gauges to check pressure and confirm it.

The refrigerator section has its own Sealed System which seems to work as it should.