648PRO Series Does Not Make Ice


  • Possible jammed ice cube
  • Low water pressure
  • Frozen ice maker fill tube
  • Warm freezer temperature
  • Water valve energized longer than fifteen seconds


  • No ice production in PRO 48 (648PRO) Series models
  • Ice maker will not cycle on 648PRO product
  • Ice maker does not work and no fault codes

Steps to Verify Issue:

  1. After the unit is on, wait 24 hours for ice production. It may take this long to see ice cubes in the ice bin.
  2. Verify the ice maker is on. Ice cubes falling into a bucket show on the display when the ice maker is on. If not, press the Ice Maker key.

  3. If "Service Ice" is flashing, the water valve energized longer than fifteen seconds and the ice maker turned off.
  4. Warm temperatures impact ice maker performance. Confirm the freezer temperature is at or below 5°F. Sub-Zero recommends 0°F freezer temperature.
  5. If the freezer temperature is higher than 5°F, see Warm Freezer Troubleshooting.
  6. Verify the condenser is clean. See Clean the Condenser for instructions.
  7. Change water filters as often as recommended, typically every 6-12 months.
  8. If installed, verify the home inline water filter is not expired. See Inline Water Filters. See also, Sub-Zero Does Not Have a Water Filtration System.
  9. Confirm good water pressure to the unit. See How to Confirm Water Pressure.
  10. Make sure the ice bin is properly installed by verifying it is level and seated in place. On some models, the ice bin presses the ice maker switch. This varies from model to model.
  11. Verify ice maker shut-off arm is in the down position.
  12. Verify the ice maker white plastic rudder arm is attached to the shut-off arm and reattach if needed. If broken or cracked, replace the ice maker shut-off arm.
  13. Make sure the water supply to the unit is on. Refer to Water Line Shut-Off Valve Location for details.
  14. Verify the ice maker is free of obstructions or jammed ice cubes. 
  15. Verify the ice maker water fill tube is not blocked. See Ice Maker Fill Tube Frozen.
  16. After freeing obstructions, turn the unit off, then on again to reset.
  17. If ice production stops often with the use of a reverse osmosis system or well water, a pressure booster or regulator may improve performance. Contact the reverse osmosis provider or speak with a plumber for suggestions.
  18. Reseat the water filter (if present) by removing and installing it. See Remove Water Filter for instructions.
  19. Reset the water filter if a water filter is present.

See also:

Note: When the ice maker is on, water may not flow into it immediately.

Refer to the product Use and Care Guide for further information.


Refer to Ice Maker Does Not Make Ice for more information and links to other product lines.

If these troubleshooting steps do not resolve the issue, service is necessary to expertly diagnose and repair the product. Contact Factory Certified Service to schedule an appointment for repair.

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