An air gap prevents dirty dishwater from backflowing into fresh water lines. But over time, ground-up food and grease can build up inside the air gap and form a clog. If water squirts out the air gap’s vent holes or you notice a foul smell coming from it, it’s time to clean it. All you need is a bottle brush and some household disinfecting cleaner.
Yank the cover off the air gap and remove the snap-in or screw-on diverter. Remove any loose food particles, then clean with the bottle brush as shown. If you still have a water leak after cleaning the air gap, clean the drain line where it meets the garbage disposer or drain wye (aka “Y”).