How should I protect my dishwasher from freezing if it will be left in an unheated space?

If the dishwasher will be left in an unheated place during winter, a service technician should cut off electrical power, turn off the water supply, disconnect and drain the water inlet line and water valve, then reconnect the line. Additionally, the plastic sump cover in the tub bottom should be removed and any remaining water soaked up with a sponge.