Measuring the air temperature in your Subzero refrigerator or freezer does not accurately reflect how well a product is being cooled. The correct way to gauge cooling efficiency is by measuring the temperature of the food itself. Water can be used to represent food in a refrigerator, while oil (such as vegetable oil) can serve as a food substitute in a freezer.

To measure temperatures in a Subzero refrigerator or freezer:

Use any liquid-safe thermometer. For refrigerators or wine storage units, place the thermometer in a glass of water, ensuring the bulb is fully submerged. In a freezer, use a glass of oil (such as vegetable oil) to cover the thermometer bulb.

For even temperature distribution, position the glass in the center of the compartment, equidistant from the front, back, top, and bottom. Allow 12 hours for the thermometer to give an accurate reading.

Is it normal for temperatures to fluctuate in a Sub-Zero refrigerator or freezer?

It’s normal for Sub-Zero refrigeration temperatures to fluctuate by +/- 5°F due to factors like an open door, humidity, or room temperature changes. Introducing new groceries or warm food can temporarily raise the temperature, but it should stabilize within a few hours. If the temperature remains too high, clean the condenser coil. Should extreme fluctuations persist after condenser cleaning and external factors are ruled out, contact John’s Heating, Cooling, and Appliance Repair for service or repairs. 678-603-7775

What temperature should I set for my Subzero freezer and refrigerator?

For Subzero products with a digital control panel, the recommended food storage temperatures are 38°F (3°C) for the refrigerator and 0°F (-18°C) for the freezer.  In products with dial control, set the dial between 4 and 6. 1 is the warmest setting, and 10 (or 7 on some models) is the coldest. Set the dial from 4 to 6 for temperatures near 38°F in the refrigerator and 0°F in the freezer.

Subzero 500 Series models with a refrigerator and freezer have two controls, one for each section. 

If there are two dials, each compartment (refrigerator and freezer) is independent. One can be off and the other on.

Storing food above 45°F is not safe.

Always allow 24 hours for your Subzero product to reach the new temperature setting.

Temperature Zones:

Temperature zones cannot be converted from refrigerator to freezer or vice versa.

Zones are the same for full-size and drawer units.

Subzero PRO Refrigeration Series units have three temperature zones: refrigerator, refrigerator drawers, and freezer.

The two refrigerator zones appear on the right-hand external display, and the freezer temperature appears on the left-side display. External displays are found on the grille above the doors.

How warm can the ambient air temperature in a home be but still allow a Subzero refrigerator to work correctly?

Sub-Zero refrigerators, excluding outdoor models, are designed to operate in environments ranging from 60°F to 90°F (15°C to 32°C). Operating outside this temperature range can negatively impact performance and may cause damage. In warmer conditions, the unit will run more frequently to maintain a cool interior.

How cold can the ambient air temperature be but still allow a Sub-Zero to work correctly?

Sub-Zero products, excluding outdoor models, are not designed to function in garages or outdoor environments where temperatures drop below freezing. These units are built to operate efficiently in ambient conditions between 60°F and 90°F (15°C to 32°C). Since refrigeration units only remove heat, they cannot generate warmth to protect the contents. If temperatures fall below the unit’s lowest setpoint, it will not function properly. This guideline also applies to wine storage units. For optimal performance, place the unit in an environment with stable, moderate temperatures.