It certainly seems mysterious when you find that your refrigerator is warm but freezer is still cold. But, like any good thriller, you just have to find the clues to solve the mystery. We’ll troubleshoot the most likely reasons for a Sub-Zero refrigerator not working but freezer is functioning fine. From a dirty door gasket to a defective thermistor, we’ll give you the clues to crack the case. 

Where to Start For a Sub-Zero Refrigerator Not Working But Freezer Is

Knowing where to start is the key to finding almost any solution. We’ll troubleshoot common causes for a Sub-Zero refrigerator not working but freezer is to implement an easy fix or arrange for a repair.

Refrigerator Door Gasket is Dirty or Damaged

A refrigerator door gasket provides a tight seal when the door is closed, keeping cold air in and preventing warm air from entering. If the gasket is dirty or damaged, the door won’t seal properly even if it stays closed. When this happens, you’ll find the refrigerator is warm but freezer is cold. 

Check the door gasket for signs of dirt or damage, like cracks or tears. While a dirty gasket can be cleaned with a damp cloth, a damaged gasket requires replacement.

Sub-Zero Evaporator Coils Are Frosted Over

Evaporator coils transport refrigerant in a cold, gaseous form as it travels from the evaporator to the compressor. Modern refrigerators have a built-in defrost system that melts any frost collecting on the evaporator coils from this cold refrigerant.

However, if the defrost system malfunctions, frost can accumulate on the coils. This frost inhibits airflow within the coils that affect the refrigerator’s temperature. At this point, you’ll notice the refrigerator not cooling but freezer works fine. If the evaporator coils are frosted over, we suggest that a professional service assesses the defrost system to determine the malfunction.

Evaporator Fan Motor is Faulty

The evaporator system uses a fan that blows cool air over the evaporator coils to help cool the refrigerator’s interior. If this fan malfunctions, either the refrigerator or freezer can experience an increase in temperature. 

If you notice these signs, the evaporator fan motor may be the culprit for why your refrigerator won’t get cold but freezer will:

  • The fan motor runs loudly
  • Fan blades don’t turn easily by hand
  • Multimeter testing of the motor reveals a lack of continuity

In either of these cases, the fan motor requires a professional replacement.

Thermistor is Defective

A refrigerator thermistor monitors the refrigerator’s internal temperature, communicating its readings to the control board that regulates the compressor and evaporator fan. If the thermistor is defective, it may not communicate the right temperatures or relay any information at all.

Once this happens, you’ll notice your Sub-Zero refrigerator not working but freezer is fine. This is because the compressor and evaporator don’t know when to provide the refrigerator with more cold air, leading to rising temperatures. If multimeter testing of the thermistor reveals a lack of continuity, it needs to be replaced.

Condenser Coils Need Cleaning

Did you know that you should clean your refrigerator’s condenser coils every 3-6 months? These coils are responsible for cooling the refrigerant that produces cool air for the refrigerator. Dusty coils are less able to cool refrigerant, resulting in a Sub-Zero refrigerator not working but freezer is fine.

Here’s how to clean Sub-Zero refrigerator coils to maintain your refrigerator’s temperature:

  1. Turn off the refrigerator’s power at the control panel.
  2. Locate the condenser coils. Most are located behind a front upper grille or lower kickplate. Remove the grille or kickplate to access the coils.
  3. With a vacuum brush attachment, remove all visible lint and dust from the coils. Vacuum in the direction of the coils to avoid damaging them.
  4. Replace the grille or kickplate.
  5. Restore power to the refrigerator at the control panel.

If these troubleshooting tips fail to solve the mystery of a warm refrigerator and cold freezer, it may be time for the Sub-Zero experts. Call Don Bacon Appliance to help with any repair.