Air gap

[Mary Ann]

I was recently told an air gap was unnecessary, and the dishwasher can drain into the disposal without the air gap. Does anyone know if this information is correct?
Thank you,
Mary Ann

[kactuskid]

I would guess it's not correct. An air gap prevents the inside of your dishwasher from becomming contaminated with backflow from the drain. It is code in most locals to install one so check with your local inspectors to be sure. In the few area's that it's not required the drain hose must be attached up high to the bottom of the countertop. Here's a link that'll show you how they are connected and why.

http://www.home-inspect.com/news/itips_4-03.html

[LazyPup]

The code requires that a dishwasher must discharge through an indirect waste system. Discharging the waste into the dishwasher port of a garbage disposal is an approved indirect waste method and therefore the air gap may not be required, however, some local codes demand an air gap on all dishwasher drain lines.

If you have a dishwasher but do not have a garbage disposal you are required to have an air gap in all cases.

Also, if you have a garbage disposal, the dishwasher is required to be connected to the dishwasher port, and may not be connected to a drain line downstream of a disposal.