Ask Me Help Desk - Install dishwasher w/o air gap

Install dishwasher w/o air gap

Hi,

I have an undermount sink and I wanted to avoid having to install an air gap on my countertop. I've seen diagrams showing dishwasher waste line being raised to the highest point inside of a cabinet and then connected to the sink waste line above the trap. I'd like to do the same operation and connect it to the disposal above the trap? Is this okay, assuming I disregard local code? Any cons to this?

Thanks,
Miguel

All plumbing codes do not need the air gap fitting. In Philadelphia, PA, by code, we install the drain hose in the cabinet to the highest point under the sink and then connect it into the disposal or "Y" tailpiece above the trap. If you do not raise the drain hose to the highest level then the water in the sink can drain back into the dishwasher when you have a full sink of water or you turn your disposal on while draining the sink. Don't forget to secure the drain hose so it does not drop.

Bentzle is correct, the air gap is required only by some codes, check your local code. If you are ignoring code then go right ahead, it should be fine. The air gap prevents siphoning in either direction so lacking this break is your only con. I never install air gaps and have had no complaints.

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Hi Miguel,

Both Bentzle and Ballengerb1 (Bob) are correct, see the image below for high loop installation, Thanks.

John

I'm going to proceed without the air gap - thanks to all for you instruction and input.

Miguel, it is never "OK" to disregard plumbing Code - and that is from 3 basic reaons:

1. If Air Gap is mandated by Code in your area, that you will create Code violation in your house
2. One day, when you are ready to sell your house, Inspector will write it up as Code violation. You will have to install it anyway. Also, it will raise red flag with the buyer suspecting other Code violations in your house.
3. Air Gap makes sense and lessen health hazard to you and your family. Few days ago, there was a post here where poster was surprised that she had waste water pouring to her dishwasher from clogged sink. Why? She had no Air Gap.

It is your call... But I would call your Inspector and ask him first.

Milo you bring up good issues. However, after looking at magazines of custom kitchen and TV shows, I rarely see air gaps installed. They just seem, kind of 1970's. So, my decision to omit one would based on pure aesthetics.

The fact that the air gap isn't required in other areas and taking into consideration the gobs of postings of successful installs indicates, to me, that it's practical enough to do an install without one. I've done the rest of my remodel without a permit, so nothing to lose at this point. I realize that when I sell the house I will be hit hard. Hopefully, however, my cash flow will be better then than it is now.

I will watch for the waste backflow into the dishwasher, that's the only thing that concerns me. I will make sure to strap that waste line as high as possible in the cabinet.

Thanks.

Miguel: as I said, it is your call. I just wanted you to give you this information for you to process. Yes, I am aware air gaps are eye sores and not mandated in all states. Just make sure you loop the discharge as high as you can and attach it to the bottom of your counter top. Good luck with your project... Drop by if you need any other opinion or help. Milo

Here is something I have wondered about for a long time. What would happen if the air gap was installed but just below the counter. You would still have about the came height but also the gap, would you think this is worth trying sometime?

Thanks milo.

Hello every one,

Though I am not a plumber by trade and would like to share the following with you guys. We moved to a new house in 2004, the boss (wife) wanted to have a soap dispenser instead of the Airgap, I removed the Airgap and installed the high loop system, 3 years ago we had a problem with our laundry machine water connections which needed to replace the wash machine box, I did replace the box instead off sweating I used the Sharkbite couplings sense then we have no problem with any one, I know some people don't like any of the above but I did it.
Note: I have worked on the airplanes for many years and know the Hydraulic system very well which has pressure of 3000 psi, Thanks.

Best Regards
John

Quote:

Originally Posted by ballengerb1

Here is something I have wondered about for a long time. What would happen if the air gap was installed but just below the counter. You would still have about the came height but also the gap, would you think this is worth trying sometime??

What would happened is that if case of clog or overflow, water would poured into the cabinet, not onto, and into, the sink. That's the only thing I can think about...

Milo,That is interested I am heading on a business trip Thursday for 3 weeks when I comeback will go to Lowe's and have a look at it sounds great. Do you know who the manufacturer is? Thanks.

John

Quote:

Originally Posted by afaroo

Milo,That is interested I am heading on a business trip Thursday for 3 weeks when I comeback will go to Lowe's and have a look at it sounds great. Do you know who the manufacturer is? Thanks.

John

I have seen it only in one Lowe's. I figured other Lowe's will carry it as well. However, I have not seen it in any other stores, yet. I do not recall the manufacturer - but I remember it was an off-brand name. I'll look for it as well...

Common sense dictates that a natural installation will, such as a regular vent as against a mechanical AAV, will outlast and give less service problems then a mechanical one.
Youcan check back on all the air gap complaints we have ever received. All of them involve counter top air gaps while we have yet to receive the first complaint on a high loop air gap. Go with the winner Sorry Milo. Tom

If the drain ever backed up then it would come out of the air gap under the counter

Quote:

Originally Posted by ballengerb1

Here is something I have wondered about for a long time. What would happen if the air gap was installed but just below the counter. You would still have about the came height but also the gap, would you think this is worth trying sometime??

I work under UPC and air gaps are mandated by UPC.

My opinion is that air gaps serve its purpose. I have 2 of them on top of my sink and never had any problem with them. Moreover, in my area, when you have pre-sale house inspection, air gaps and T&P valves are the two most common Code violations called by attending Inspector.

Tom, I have nothing against high loops. In fact, I LOVE high loops. We make good living replacing them with air gaps. :-)

Bob, in the situation you describe in the above post, if your drain is blocked and water will raise in your sink to the rim, it will overflow thought the under the counter mounted air gap right into your dishwasher. I just happened to see this happen couple of times...

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Quote:

Tom, I have nothing against high loops. In fact, I LOVE high loops. We make good living replacing them with air gaps. :-)

Certainly not because they fail. In asll the hundreds my company has installed and all the high loops we have advised here in ANHD we have yet to receive our first complaint or call back. Ya just can't argue against success. Milo.
Bob,
There is a in the wall DW air gap.
It's called a Johnson Tee, (see image) Regards, Tom