The Sub-Zero name is synonymous with superior quality, so when you find your Sub-Zero 648PRO not dispensing ice, it can certainly be disappointing. Fortunately, there are usually simple reasons for the problem. From incorrect freezer temperatures to dirty condenser coils, we’ll troubleshoot the most common causes and how to fix them.

Sub-Zero 648Pro Not Dispensing Ice?
Here’s Where to Start

When your ice maker doesn’t make ice, it can be hard to know where to start. But there are usually several common causes for a Sub-Zero 648PRO not dispensing ice, and they often have DIY fixes. Here’s how to pinpoint the problem and fix it quickly.

#1 Ice Maker is Turned Off

While it may seem overly obvious, an ice maker that’s turned off is actually one of the most common reasons for a lack of ice. Make sure that your ice maker is on if the refrigerator is newly installed or turned on after a period of disuse.

To turn on your Sub-Zero ice maker, press the ICE MAKER button on the refrigerator’s control panel. When it’s turned on, a picture of ice cubes falling into an ice bucket will appear on the freezer’s external display panel.

#2 Freezer Temperature is Too High

When you notice your Sub-Zero ice maker not working, we also suggest checking the freezer temperature. If it’s over 5°F, it may be too warm for the ice maker to produce ice.

Make sure your freezer temperature is at or below 5°F.  Sub-Zero recommends a freezer temperature of 0°F for optimal ice production.

Sub-Zero ice maker not working

Image: Sub-Zero Wolf


#3 Ice Maker is Jammed

A lack of ice can also be due to a Sub-Zero ice maker freezing up from ice jams. As an ice maker produces ice, there may be small amounts of water or slush that are not completely frozen as the ice is harvested. This slush can freeze on the ice maker and block new ice from falling into the ice bucket.

The best way to safely remove ice jams without harming ice maker components is to defrost the freezer. The 648PRO series has a manual defrost feature that enables the refrigerator to remain on while the freezer defrosts. Refer to your user manual for specific instructions when using this feature.

#4 Water Filter Needs Replacement

If your ice maker is still producing ice, but not as much as usual, check the water filter. A Sub-Zero water filter screens out particles and contaminants from your home’s water supply to produce clean drinking water and ice. However, if the filter becomes clogged with these particles, it can also restrict the amount of water that the ice maker receives, reducing ice production.

To avoid this outcome, it’s recommended that you change your Sub-Zero water filter every 6 months. You may need to do so more frequently if ice production is limited, or your ice and water have a bad taste or odor.

Sub-Zero 648PRO not dispensing ice

Image: Sub-Zero Wolf


#5 Condenser Coils Are Dirty

Dirty condenser coils can also be responsible for an ice maker not making ice. These coils help cool refrigerant to create cold air for the freezer. However, if the coils get coated in dust and dirt it can prevent them from sufficiently cooling refrigerant. When this happens your freezer temperature could warm and prohibit the ice maker from making ice.

It’s recommended that you clean Sub-Zero condenser coils every 6-12 months to prevent a buildup of dust and dirt. Follow these simple steps for a quick cleaning:

  1. Turn off the refrigerator by pressing and holding the POWER button on the control panel.
  2. Access the condenser coils by opening the grille at the top of the refrigerator. Hold the grille from the bottom and pull it forward and up to keep it open.
  3. Use a soft brush vacuum attachment to vacuum the coils in a vertical, up-and-down direction.
  4. Replace the grille by tilting it downward and pushing it into place.
  5. Press and hold the POWER button to restore power to the refrigerator.


If these troubleshooting tips still leave you with a Sub-Zero 648PRO not dispensing ice, then it may be time for an ice maker repair. Call Don Bacon Appliance Service for fast and professional assistance.