Dishwasher Is Emptying Slowly After Installing Garbage Disposal

Knockout Plug

• The knockout plug, which resembles a molded plastic plug, is included with most new garbage disposers. It should have been removed during installation. Leaving the knockout plug in place slows down water drainage from the dishwasher and is the probable cause of the water issue.

Remove Knockout Plug

• Disconnect power to the garbage disposer and the dishwasher before making any modifications to the system. Then disconnect the disposer at the dishwasher inlet underneath the sink. Use a hammer to tap a flat blade screwdriver until the knockout plug is loose and remove the plug. Reconnect the disposer to the dishwasher inlet and restore power.

Air Gap

• Many garbage disposer manufacturers recommend using an air gap to keep dishwasher wastewater from entering the sink and vice versa. If the dishwasher is draining slowly once the garbage disposer is installed and the knockout plug removed, check the air gap. Lift the air gap lid and clean out the air gap hoses.

Drain Line

• Clear the garbage disposer drain line flushing it out after garbage disposer installation. Turn on the cold water in the sink and run the garbage disposer until the grinding slows. Waiting an additional 15 seconds after that completely flushes out the system. Disconnect the drain line from the dishwasher connecting to the garbage disposer and clean out the drain line removing any remaining debris, and then reconnect the line. Contact a plumber for assistance if the dishwasher continues draining slowly.