Get matched with top dishwasher installation pros in Whitfield, MS

A clogged air gap can cause a dishwasher not to drain. There are, however, other potential issues that can lead to improper drainage. For example, if you have attached the air gap to a garbage disposal and forgotten to remove the knockout plug, wastewater may backflow into the dishwasher. Check that the air gap is installed properly, and then look for clogs in the air gap and dishwasher filters. 

If your dishwasher isn’t draining, some common causes include a clogged drain filter, drain hose, or air gap. Also, if you have a garbage disposal, a clog in the disposal can back up your dishwasher since they share plumbing, as can a clog in your kitchen sink’s plumbing. A handy DIYer may be able to figure out how to unclog a dishwasher, but you may need to call in a plumber if you can’t locate and clear the clog yourself.

To clean an old dishwasher without a filter, start by removing the bottom rack to access the drain area. Use a damp cloth or sponge to wipe down the interior, paying special attention to the corners and crevices where food particles and debris can build up. Pour a cup of white vinegar into a dishwasher-safe bowl and place it on the top rack, then run a hot water cycle to help break down grease and grime. After the cycle, sprinkle a cup of baking soda across the bottom of the dishwasher and run a short hot water cycle to deodorize and further clean the interior. 

Water may linger at the bottom of your dishwasher if the cycle is interrupted or if there’s a clog in the system. Begin by pressing and holding the cancel button to ensure the cycle finishes. You may need to check the filter, hose, air gap, and garbage disposal for clogs if it still doesn't drain. If the problem persists and there is no visible clog, a professional will need to assess and fix the problem for you.