Is dishwasher drain hose connected to a garbage disposal?
For many dishwashers, the drain hose is connected to the disposal and the knockout plug must be removed from the disposer inlet. Is the drain system blocked? Run the disposer to clear the drain system. Do you have an air gap at your sink? Check to see if the air gap is blocked by foreign material. To clean the drain air gap, follow the cleaning instructions provided by the manufacturer. With most types, you lift off the chrome cover, unscrew the plastic cap, and then check for any soil buildup. Clean if necessary. Is there a loop in the drain hose less than 20″ (50.8 cm) above the floor? Make sure the drain hose is looped so that it touches the underside of the counter before connecting to the sink drain or disposer. Is there a kink in the drain hose? Replace a kinked drain hose. Did you reuse an existing drain hose? Make sure to use the new drain hose that came with the dishwasher. Is the sink drain clogged? If the sink is not draining well, a plumber may need to be contacted. Most di