Sub-Zero General Poor Cooling / Capacity Loss

Refrigerator and/or freezer temperatures are too warm; unit runs but cannot reach setpoint.

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Dirty condenser coil, Failed condenser fan motor, Door gaskets leaking warm air, Low refrigerant charge or sealed system leak

How to Fix / Troubleshooting

Safety first: Unplug the unit before cleaning coils or working near moving parts.

Step 1 – Clean condenser coil

Remove the grille and thoroughly vacuum the condenser coil with a brush attachment.
Do this at least twice a year, more often with pets.

Step 2 – Check condenser fan

Restore power and confirm the condenser fan runs whenever the compressor is on.
Replace the condenser fan motor if it is not running or is noisy.

Step 3 – Inspect door gaskets

Check all door gaskets for tears, gaps, or hardened sections.
Close a sheet of paper in the door and pull; if it slides out easily, the gasket may not be sealing and should be replaced or adjusted.

Step 4 – Look for sealed system symptoms

If the compressor runs almost constantly, the condenser is warm, but the evaporator only frosts partially, there may be a refrigerant issue.
Sealed system work must be done by an EPA‑certified Sub‑Zero technician.

Repair Difficulty

Hard 4/5

Required Part

Condenser Coil

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