Depends on your dishwasher and your location. Some newer high end dishwashers are designed so that they don't need them, and some local codes don't require them. Others do. Our local building code in OC California requires air gaps regardless of the model of the dishwasher.

I never heard of an air gap before these forums. I have never had such a thing.

yep. same here. i had to look it up.

You don't want one trust me. They are a bugger to keep clean.

I had one in my old kitchen, and the first thing I asked the plumber was if we could get rid of it, No problem - he ran the DW drain hose high up just under the counter, just like the directions said - no more air gap.

They are disgusting, dirty and worthless. In the four years I've been without one I haven't had a single backflow or clog. I was always cleaning the cruddy air gap, it just never worked.

If you don't need one, don't get one, and if you have one, get rid of it. Some people here have the air gap installed, and then after the inspection, remove it and put in a soap dispenser.

We were able to get a waiver in Sunnyvale, CA. Talk to your city building dept.

Some people install them just to pass inspection and then replace them with a soap dispenser. As long as you have a high loop in your drain hose, you don't really need the air gap but some municipalities require them nonetheless.

This post couldn't be more timely. I am about to have my countertops fabricated and I've been obsessing about the stupid air gap. I hate the silly crusty mess of a thing. I was considering switching out the chrome one I bought with a black one so it would better blend into my counters. Now I'm thinking -- blow it off altogether! WAHOOOO!

Babka --

That's great you were able to get a waiver from your city building department. What exactly did you say to them?

We'll have a Miele dishwasher which technically doesn't need an air gap.

Thanks in advance for your advice!

We had to provide documentation to the city inspector that our Miele DW (actually 2) has the air gap function built in, so we didn't have to install one (or two). Because city code requires an air gap with dishwashers, our GC routinely installs them, & was surprised about the Miele.

gizmonike --

Thanks for the helpful info!

Our city hall requires them, even though our new Asko has the high loop in the drain tubing that negates an air gap. Since our DW was installed on an exterior wall, my plumber was able to put an air gap that goes directly outside, so we didn't need an extra hole in the counter. In essence, we have an air gap, but you don't see it. Kind of cool.

My plumber said many folk around here will do the hole for the air gap, install it for inspection, then remove it afterwards and replace it with a soap dispenser or something else.

Kind of like those folk that remove the flow restrictors, LOL.

Just like gizmonike said. Our GC as well as our KD had never heard that you could get a waiver with some dishwashers. Ours is a Miele also. We did ours almost 2 years ago, and more brands of dishwashers have built in anti-siphons now.

I STILL don't understand what the heck an air gap is! Is it only CA that requires them? What are the supposed dangers to those of us without them? It's odd because it's not like New England is generally lax about building codes, I don't think.

Now that I think of it, I've also never heard of anyone needing a permit or an inspection for dishwasher installation, but maybe those posts are about new building projects.

I believe it's purpose is that if the dishwasher overflows, the water will go up the hose and out the air gap, thus into the sink instead of overflowing onto the floor. It only happened to me once when DH didn't install the disposal correctly...since my air gap wasn't pointing directly into the sink (it turns)the water went all over the counters instead. He then re-installed the disposal and it's never happened again.

Actually, it is to provide a break between the water supply and the drain system. It is designed that in the event that the drain is clogged, the waste will have an outlet other than the water supply system in your home. The other appliances in your home such as the dishwasher, sinks, etc have these built in naturally. This is also why the faucet must be higher than the "flood level" or the top of the rim of your sink. If in the event your sink fills, there is a potential situation where the waste in the sink can backfeed into the water supply system.

Trust me. It is there for a reason. The high loop hose will work if installed properly but sadly, most are not.

SP

Small oops on that last message, I meant clothes washer, not dishwasher.

SP