Answer Jeff, icemakers operate off of temperature. When you replace an icemaker, it will need to cool down to about 0-5 degrees F, before it will cycle and fill with water. This may take several hours depending on how cold it is in your freezer. Once it fills with water, the warm water opens a thermostat inside the mold of the icemaker, it then has to freeze that water until the thermostat is closed and the harvest cycle begins. Typically it takes 6-8 hours for an icemaker to cycle and produce ice. Read More... Answered by AppliancePartsPros.com | Tuesday, October 15, 2019