F4 code on Haier ice maker; unit may stop mid-harvest or drop incomplete ice.

Safety first: Disconnect power before working near the evaporator or moving parts.

Steps to correct:

• Check ice thickness: If ice is excessively thick, adjust the ice thickness sensor to a thinner setting and clean the sensor as needed.
• Inspect harvest heater: Verify the heater warms the evaporator or tray during harvest. If not, test and replace the heater as needed.
• Examine harvest mechanism: Check for binding or obstructions in the rake arms or tray rotation. Remove any jammed ice.
• Test harvest motor: Access the harvest motor and test for continuity and proper operation. Replace if seized or electrically open.
• Reset and test: After adjustments and repairs, restore power and observe a full harvest cycle to ensure F4 does not recur.

When to call a technician: If mechanical components are difficult to access or if the control board fails to initiate harvest, professional service is recommended.