An ice maker having a refrigeration system, a water system and a control system. The refrigeration system includes an ice formation device. The water system supplies water to the ice formation device, and includes a water reservoir (e.g., a sump or float chamber) for holding water to be formed into ice and a discharge valve in fluid communication with the water reservoir. The control system includes an ice level sensor adapted to sense the ice level in an ice storage bin, and a controller adapted to cause water to drain from the water reservoir when the ice storage bin is full. Substantially or all of the water remaining in the water reservoir is drained such that while the ice maker is not making ice the water reservoir is empty of water.