Hello,

When we run our dishwasher, we are getting overflow through the air gap. I bought a new air gap to replace the old one, but don't really know if this will solve the problem. Any advice? Thanks!

When that happens to me, I use a long brush and clean out the pipe leading to to the air gap. :)

You have a blockage in the hose (the big one) between the air gap and the sink or disposal. Remove and clean.

The air gap is a back flow preventer. It prevents domestic water from being contaminated with drain water. High loops are sometimes used if code allows. It's based on the principle that drain water doesn't travel up hill.

Hello,

When we run our dishwasher, we are getting overflow through the air gap. I bought a new air gap to replace the old one, but don't really know if this will solve the problem. Any advice? Thanks!

Let's take a look at your present air-gap. . In the top of an air gap is an insert with two holes. Inside the air gap are two divisions. One division connects to the inflow side of the air gap (from the dishwasher) and the other connects to the outflow side (to the disposal). If the top insert is put in wrong, water will flow from it when the dishwasher empties. For correct operation of the air gap both holes in the insert need to be positioned over the outflow division of the air gap.


In case you ever want to do away with that pesky counter top air gap and install a high loop Air gap.(see image) I'll be more then happy to help.
Note: In all the hundreds of high loop air gaps that my company's installed we have yet to get our first complaint or service call. This holds true in the high loops that we have advised installing on The Plumbing Page right here.
Good luck, Tom