Despite the fact that appliances are heavy and bulky, they are delicate little butterflies inside. Okay, maybe not that delicate, but they can be easily ruined. There are a lot of components inside that can be damaged by forceful movement or from being dropped, even a short distance. If you hire reputable movers they will likely have the knowledge needed to safely unhook and move these items. However, if you are paying by the hour you might want to unhook and have them ready to go to save time and money.