Bellingham Home Inspections (King of the House) — Dishwasher Air Gap Device

At a dishwasher the air gap device is traditionally put in the system to assure a sanitary environment for our cups, saucers, plates and silverware and to protect against a cross-connection that could contaminate potable water. Properly designed and installed, an air gap allows water to flow only in the desired direction.

The photo below is a very basic diagram of an air gap installation at a dishwasher and a kitchen sink.

For a close-up of the inside of the air gap device itself, look at the diagram below. As you can see, this is not simply a continuous hose used as a drain. There is a gap in the line — the air gap.

More often than not, when there is an air gap device, you will see it at the sink. It will look like this shiny contraption in the photo — often installed next to or where the hose sprayer used to be.

Those are the basics but, even if you do not see one of these devices at the sink, there might be an air gap after all. Sometimes the air gap is built-into the dishwasher or it could look different and be outside at the exterior wall of the home — a device known as a Johnson Tee. You can learn more about this device by performing an Online search.

Thanks for stopping by,

Steven L. Smith

Rev: September 1, 2013