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Undercounter Ice Maker UC-15I Troubleshooting


  • UC-15I ice maker not making ice or produces hollow or small ice cubes
  • Single, couple, or few cubes of ice made during each ice production cycle
  • Ice maker not harvesting or dropping eight ice cubes at a time, not producing full batch of ice
  • Ice quickly melting in UC-15I
  • Water pouring into ice bin of Undercounter Ice Maker


  1. Verify the ice maker is turned on.
  2. Verify no indicator lights are lit on the control panel.
  3. Replace the water filter if the Replace Filter indicator is lit. See How to Replace or Reset UC-15I(P) Water Filter.
  4. Verify that a Sub-Zero water filter is being used. Third-party water filters have not been tested and might lead to poor performance.
  5. Make sure the unit is turned on for at least 24 hours, as ice makers may not cycle until 24 hours pass.
  6. Verify the unit's condenser has been cleaned within the last 6-12 months. Clean the Condenser as needed.
  7. Make sure the delay function has not been initiated. Refer to Undercounter Ice Maker UC-15I Delay Function for more information.
  8. The water must be turned on. Shutoff might be:
    • Under the kitchen sink.
    • Under the refrigerator behind the kickplate.
    • In an adjacent cabinet.
    • In the basement near the water filtration system.
  9. Low or no water pressure may prevent ice production. Pour a cup of water behind the ice maker curtain. If the spray changes, it is an indication the unit is not getting enough water pressure.
  10. High ambient room temperatures or installing the unit in an area that receives a lot of direct sunlight can cause the ice to melt quickly. The ice bin is not refrigerated.
  11. Reset the water filter by removing and installing it.
  12. If ice production stops often when using a reverse osmosis system or a well water system, consider adding a pressure booster or regulator. Contact the reverse osmosis provider or speak with a plumber for suggestions.
  13. Make sure the drain line is not kinked or looped.
  14. Verify unit is not on a generator. Proper voltage must be supplied for unit to work properly.
  15. Make sure the unit is properly cleaned and sanitized regularly. See UC-15I and 315I Cleaning.
  16. Let 24 hours pass after steps are complete and check for ice production.
  17. If the ice maker issues continue after the troubleshooting steps above are complete, service is necessary to expertly diagnose and repair the product. Contact Factory Certified Service to schedule an appointment for repair.
  18. See also:

Refer to the product Use and Care Guide for further information on condenser cleaning, bin thermostat operation, and cleaning and sanitizing instructions.


Need further assistance? Contact Customer Care at 800.222.7820 or provide your information below and request a Customer Care representative contact you.

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