When water is shooting out of the air gap, there are two basic causes:

  1. Your dishwasher drain is clogged. This can be corrected by cleaning the discharge hose between the air gap and the disposal.
  2. If the problem began when you replaced the garbage disposal, then most likely the discharge plug needs to be removed. The plug is part of the disposal so that there will not be an open hole if you do not have a dishwasher.  To remove it, simply disconnect the disposal from power and use a hammer and a screwdriver to knock it free. After removing the plug chip from the disposal, restore power to the machine.