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Bruce Page
07-23-2011, 4:28 PM
Is there an alternative to the dishwasher “Air Gap” cap that is normally mounted to the top of the sink (at least here in NM)? We are going to do a complete kitchen remodel and LOML has said that she does not want that chrome knob sticking out of the new sink.

Jerry Bruette
07-23-2011, 4:53 PM
I'm pretty sure the local green BORG sells a soap dispenser that doubles as the air gap unit.

Jerry

Mike Henderson
07-23-2011, 5:49 PM
You probably aren't having this inspected by the local code people, so I think you could mount the air gap under the counter top. Just be aware that if there's a clog in the drain, things will get wet.

Mike

glenn bradley
07-23-2011, 6:09 PM
No problem . . . just skip the dishwasher :D. I am no plumber but, have seen a 'high loop' used instead in homes that happened to be about 25 years old in SoCal; newr and older homes may use them as well(?). I have no idea if the requirement is regional, functional or maybe 'ease of install' driven.

Bruce Page
07-23-2011, 7:30 PM
Glenn, I'm the dishwasher filler upper so that won't work! Looking around on the net, it looks like some new dishwashers no longer require the external vent. I'll have to check if the new KitchenAid we have on order has it. The above the drain-level loop is also common.

David Helm
07-23-2011, 8:25 PM
Air gaps or high loops are required by most AHJs. The idea is to keep dirty water from being drawn back into the potable system. For a high loop to work, it has to be attached to the underside of the countertop so the loop is above any water in the DW. The high loop acts in the same way as the air gap. It is an antisiphon device. The good news is that some dishwashers (usually higher end European ones) have a built in air gap.

Von Bickley
07-23-2011, 10:05 PM
Bruce,
I have been around a lot of homes being built in central SC, and I have never seen a vent cap like you mention.
The kitchen drain is vented thru the normal plumbing and the dishwasher is just connected to the drain under the sink. No special vent cap.

Mike Null
07-23-2011, 11:36 PM
Bruce

I retired from the appliance manufacturing business and never saw such a thing. (on our products or any of our competitors)

In most cases that drain hose is connected to the disposer.

Mike Henderson
07-23-2011, 11:46 PM
Bruce

I retired from the appliance manufacturing business and never saw such a thing. (on our products or any of our competitors)

In most cases that drain hose is connected to the disposer.
It's required by code in certain areas. Your area may not require it.

Mike

David G Baker
07-23-2011, 11:59 PM
Haven't thought about the air gap for years. My dishwasher does not have one and didn't have on inclided with it or mention it in the installation instructions.

Bruce Page
07-24-2011, 12:25 AM
Every place that I have lived that had a dishwasher has had the sink top vent, I sure want to ditch it with the remodel. I like the idea of the high-loop David describes, it sounds easy enough to do.

Matt Meiser
07-24-2011, 5:52 AM
Neither our first house or this house had one. Both have kitchens build in the 90's. My parents did in their 1960's kitchen but its gone after their remodel. All just have the high loop under the counter. I assumed they were no longer needed with modern dishwashers.

Dave Ogren
07-24-2011, 10:14 AM
I just put in a new dishwasher (Kitchen Aid) about 5 weeks ago.Here the code only requires that you use a S.S. braided intake hose.
Good Luck,
Dave

David Helm
07-24-2011, 10:47 AM
I guess I'll say it again. It is not a vent. It is an antisiphon device that prevents dirty water from being drawn back into the potable system. It doesn't come with the appliance. It is a separate purchase. Most dishwashers installed without it are installed by the homeowner who doesn't know about the requirement. They have been in the code for quite a few years.

John M Wilson
07-24-2011, 11:15 AM
It is an antisiphon device that prevents dirty water from being drawn back into the potable system.

On my dishwasher, the discharge line (which is the one that you show with the antisiphon vent on the drawing) is completely separate from the water supply line.

The potable water supply opening is on the side of the dishwasher, about an inch above the bottom of the door opening, which would be the maximum high water mark of the tub.

The drain is in the bottom of the dishwasher. There will always be an air gap between the supply line and the drain line -- it's just internal to the dishwasher. Backflow into the potable water system would seem improbable, if not impossible.

I think perhaps the antisiphon is to prevent the dishwasher from siphoning dirty water out of the sink (or garbage disposal) back into the bottom of the dishwasher, thus rendering your clean dishes dirty again, or causing a nasty overflow/spill.

While I can't speak to code, which varies so much from place to place, I do think that your assertion that most dishwashers are installed by homeowners might be overstating it a bit. I have been in many, many new construction homes over the last few years, where the dishwasher was not installed by the homeowner, presumably built and inspected to code, and have seen an air gap in none of them.

The only places I have seen air gaps is in homes that had the dishwashers installed prior to 1980 or so...

Is it possible that the manufacturers made a design change and eliminated the need?

Bill ThompsonNM
07-24-2011, 11:18 AM
Actually David, Bruce is referring the airgap which an antisiphon device which prevents waste water from being drawn into the dishwasher-- not into the potable water system. That's a different device on the input line. I suspect most homeowner installed dishwashers are replacements not original. So if the original didn't have an airgap the replacement won't and the original probably passed inspection even if it isn't up to code. Individual codes vary widely on this point as a few quick google searches reveal.

Peter Stahl
07-24-2011, 2:01 PM
Ask the Pro's over at Terry Love's plumbing forum. Every house I've ever been in my area do not have the vent they show in the instructions.

Bill Cunningham
07-24-2011, 9:07 PM
I've never seen one of those... I installed our dishwasher with our kitchen reno about 5 years ago, and the instructions never mentioned anything like that! My previous dishwasher worked flawlessly for years over 40 years. She never complained at all:D

dave toney
07-24-2011, 9:23 PM
OK, I'll ask, what is the purpose of this device?
Dave

Bruce Page
07-24-2011, 11:05 PM
OK, I'll ask, what is the purpose of this device?
Dave
Near as I can tell it prevents standing water in the sink from reentering the dishwasher.

Mike Null
07-25-2011, 7:10 AM
My responsibility was on a national basis in product management and never did I hear or see such an arrangement. Codes were something we were concerned with. This is not necessary and is nothing more than make work code for the benefit of local plumbers. It is separate from the dw so the mfr need not be concerned if the locals want to enforce such a thing.

It has nothing to do with the potable water supply.

Dishwashers have check valves in the pump/drain to prevent backflow.

Mike Henderson
07-25-2011, 10:30 AM
My responsibility was on a national basis in product management and never did I hear or see such an arrangement. Codes were something we were concerned with. This is not necessary and is nothing more than make work code for the benefit of local plumbers. It is separate from the dw so the mfr need not be concerned if the locals want to enforce such a thing.

It has nothing to do with the potable water supply.

Dishwashers have check valves in the pump/drain to prevent backflow.
That's very interesting. Around here, all houses have that vent so I assumed it was required by code. I'll have to check into that just to find out.

Mike

Dan Hintz
07-25-2011, 10:34 AM
In FL, air gaps were not required... but we have one in our house in MD (and I hate it). When I initially looked into removing it, my understanding was it was required to keep the flow above the point of the garbage disposal (avoiding backups from the sink into the dishwasher). If your GD had an input for a dishwasher drain valve, you could use that instead of the airgap.

It has been several years since I looked, so my memory could be very rusty, but I remember thinking the airgap would disappear when I got around to remodeling the kitchen. It would be replaced with a sprayer hose, an item I'm bugged about by SWMBO.

Bruce Page
07-25-2011, 1:22 PM
Our house was built in the late 70’s. I think the air gap sink wart was standard practice at the time in New Mexico. LOML watches HGTV a lot and says she never see’s the wart on remodel jobs.

Craig Matheny
07-25-2011, 6:51 PM
203062Got you covered no pun intended do a search on yahoo for "West Brass Air Gap Kit with Modern Soap Dispenser D2170P-07" and all is happy

Happy Wife Happy Life