Ice maker runs continuously without cycling off, ice bin overfills or ice becomes very hard and frosted.

Safety: Unplug the unit before inspecting sensors or boards.

• Test bin full function: Manually lift the shutoff arm (if fitted) or block the optical sensor with an object to simulate a full bin. The unit should stop. If it does not, the sensor or control board may be faulty.
• Inspect sensor alignment: Ensure optical sensors face each other correctly and are not loose.
• Replace faulty sensor: If the sensor never signals full, replace the bin full sensor assembly.
• Check control board: If the sensor tests good but the unit still runs continuously, the control board relay may be stuck and the board should be replaced.