Dishwasher - Cleaning Your Air Gap
The air gap is a chrome plated cylinder located on the back of the sink where the faucet is located. Not all areas have plumbing codes that require an air gap, so you may not have one installed with your dishwasher drain. The air gap prevents water from a clogged drain from backing up into the dishwasher.
To clean your air gap, follow the steps below:
Remove the chrome cover of the air gap. The chrome cylinder/cover should lift right up from the air gap.
Unscrew the plastic cap.
Remove any material that may have accumulated in the air gap. Rinse out the plastic cap.
Check the hose from the air gap to the sink drain or garbage disposal to make sure it is not clogged.
View a short video about clogged air gaps: