The part(s) or condition(s) listed below for the symptom Refrigerator ice maker overflowing are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The water inlet valve requires a minimum of 20 psi to shut off properly. If the water pressure is too low, the valve may not close fully once the power is shut off. As a result, the valve will leak water into the ice maker and cause the ice maker to overflow. Check the water pressure to determine if it is at least 20 psi. If the water pressure is sufficient, the water inlet valve is likely defective. The valve may not shut off all the way or may be stuck open, causing water to leak through the valve. If the water pressure is sufficient, but the ice maker is still overflowing, replace the water inlet valve.
The water inlet valve supplies water to the refrigerator ice and water dispenser. The valve requires a minimum of 20psi to work properly. If the water pressure is too low, the valve may not close fully when the power is shut off. As a result, the valve leaks water into the ice maker, causing it to overflow. Check the water flow and test the pressure to determine if it is at least 20 psi.
One component of the ice maker assembly might be defective. Since many of the ice maker components are not sold separately, you may need to purchase and replace the entire ice maker assembly.
Refrigerator icemaker kit, The kit includes the fill cup, 4 pin wire harness adapter, and tube. If the icemaker is not working, make sure the freezer temperature is around zero degrees Fahrenheit. If the refrigerator temperature is correct, the icemaker or water valve could be defective.