Air Gaps are able to be taken apart to clean if need be. Remove the chrome bezel and unscrew the top of Air Gap and inspect for buildup, most likely you will find the problem there.
DUNBAR
Website Moderator
» This message has been edited by DUNBAR on 30 August 2005
After you do what Dunbar suggested, check for any kinks in the tubing or slight blockages this can cause those air-gaps to spit or water backing-up in them.