How to Connect a Dishwasher to a Garbage Disposal

Check that both the dishwasher and the garbage disposal are turned off before starting work. Ensure they won't be turned on accidentally while you're working by turning off the circuit for both appliances at the main circuit breaker.

Plan the route for the dishwasher drain hose to the garbage disposal. If the drain hose has to run through cabinets, mark on the side of the cabinet and drill a hole for the dishwasher hose using a spade bit and power drill. Sand down the edges of the hole with a file or sandpaper so that the sharp edges won't damage the hose and cause it to leak.

Punch out the knockout on the side of the garbage disposal with a screwdriver. Remove the knockout tab and throw it away.

Trim off the end of the dishwasher drain hose to the correct size for your garbage disposal with a utility knife. Markings are found on the side of the drain hose to help you determine where to cut.

Slip the end of the drain hose over the nipple on the garbage disposal. Secure the end with a clamp. Tighten as needed with a screwdriver.

Elevate the center part of the dishwasher hose and secure it either to the side of the cabinet or the wall with a hose clamp. The central part of the hose should be taller than the connection at the garbage disposal, which helps prevent backflow of dirty water back into the dishwasher.

Restore power for both the dishwasher and garbage disposal. Run a small test wash in the dishwasher. Watch the dishwasher drain hose and garbage disposal connection during the drain cycle for leaks. Tighten the hose clamps if needed.