Dishwasher Vent

[Marti]

I am an amateur handy man around the house. I am remodeling our kitchen and have ordered a new counter top and sink. However, I don't want that nasty vent sticking up above my new quartz counter and sink.

Can I mount the Y pipe under the counter instead or is that to low? Do I have to take the vent all the way under the floor to the outside of the house? (that would mean the vent hose would drop below the dishwasher) :confused:

Any advice will be appreciated.
Marti

[DUNBAR]

Air Gaps are code in KY for keeping that "nasty" germ/bacteria laden waste from ever reentering your dishwasher in the event of a clog.

I'm reworking a drain system after christmas where somebody dropped the Air Gap under the sink, lost its effectiveness and destroyed the base of the cabinet. I'm not coming back until all the black mold is gone, new surface to bottom of sink base.

Air Gaps serve more purpose in the lines of backflow safety than what the end user is willing to understand.

It protects in the event of a clogged kitchen sink drain; fluid dynamics will send that reversal of flow back to the dishwasher.....not knowing it has happened.


You are gambling at best....

[ToUtahNow]

Marti,

The dishwasher is required by the Uniform Plumbing Code but not by the International Plumbing Code. Oddly enough Washington adopted all International Codes with the exception of the Plumbing Code where they adopted the Uniform Plumbing Code. I reviewed Washington's amendments to the UPC and there was no exception for dishwasher air gaps. In other words you must install a dishwasher air gap to be legal.

Mark

[BAPlumber]

when I was plumbing in Washington, a "Johnson Tee" was an acceptable alternative to the air gap.

http://www.dalspc.com/Sub/pdf/Cat2005.pdf
a johnson tee is on page 22.

[plumberscrack]

I looked on page 22 at the Johnson Tee.

I have no idea what the hell that thing is or what it's supposed to do.:confused:

Please clue me in

[NHMaster3015]

You don't need to mount the thing above the counter. It can be mounted just below with the proper hardware. Interestingly enough, quite a few new dishwashers have a trap and air gap built in. the ipc wants the drain hose looped and clipped to the highest point under the counter top, but this effectivly double traps the fixture, which is a code no no. Sometimes you have to do a it of explaining to the inspector and perhaps have a copy of the code handy.

[ToUtahNow]

I looked on page 22 at the Johnson Tee.

I have no idea what the hell that thing is or what it's supposed to do.:confused:

Please clue me in

I don't think anyone has installed one in our area in the last 40-years but they are an approved and listed air gap under the UPC. Just like a standard air gap they must have a critical line which is higher than the flood rim of the fixture. The main difference is unlike a standard air gap which is installed in the counter top or sink ledge and then drained via a 7/8" hose to the dishwasher the Johnson Tee has a separate 1 1/2" trap and riser in the wall that the Johnson tee sits on. You then have copper in-wall piping running from the dishwasher area and then making a loop above the Johnson Tee and tying in to the top of the Johnson Tee. The vent can then either be through the splash above the sink or out through the exterior wall. They are a good system but add quite a bit of cost to a dishwasher rough in.

Mark

[ToUtahNow]

Okay I found some photos of a Johnson Tee installation and vent.

Mark

[ToUtahNow]

Okay never mind it looks like they are no longer available even if you wanted to install one.

This is from the IAPMO Listing pages:

Generated On: 12/21/2007</I>

File Number: 1926
Product Description:Airgap Fittings (Dishwasher Waste)
Listee: JOHNSON INDUSTRIES, INC.
1015 S MYRTLE ST
SEATTLE, WA 98108
CANCELLED
Expiration Date: no data
Identification:
Manufacturer's name or trademark, model number, Flood level, and UPC® certification mark.


Characteristics:
Dishwasher drain airgap made of listed plastic DWV material. The airgap meets or exceeds the requirements of IAPMO Property Standard PS 23 and shall be installed in accordance with the manufacturer's instructions and the provisions of the latest edition of the Uniform Plumbing Code.
Models:
6/18/04-file canceled at applicant's request/no longer producing, JUNE PRC - tk AG-4P Johnson Tee

Additional Companies:


Additional Company Info:





Mark

[NHMaster3015]

Thank god we don't have to do that here. How long would that trap last on an outside wall in our weather.

[DUNBAR]

You don't need to mount the thing above the counter. It can be mounted just below with the proper hardware. Interestingly enough, quite a few new dishwashers have a trap and air gap built in. the ipc wants the drain hose looped and clipped to the highest point under the counter top, but this effectivly double traps the fixture, which is a code no no. Sometimes you have to do a it of explaining to the inspector and perhaps have a copy of the code handy.



I've read your response and can't understand it. Can't tell what you're expressing.


The only way an Air Gap serves its purpose is only when the device is above the flood level rim it serves. Any Air Gap open to the free atmosphere at the dishwasher (moisture, possibility of error in a concealed location) would be at a minimum, 2" below flood level. The "Critical Level" is the point at where the device may become submerged and backflow may occur. These are predetermined settings set forth by all regulating commissions.



Clipping the hose and high looping under the sink is the same as draining a pool with a garden hose draped over the edge, the end of that hose at a lower elevation to provide fluid dynamics to start the siphon process.

The first plunger to the sink drain and/or the waste level rising to the flood level rim at which the fixture will over flow, it will travel to the dishwasher.

Built-in check valves on dishwashers do not supercede local authority codes in the removal of an Air Gap.


An Air Gap is mandatory on all commercial industrial applications on the idea and premace of dishtank equipment, there is absolutely no reason the code should be relaxed down to the residential level just because the likelihood is less.

In my opinion in all that I've seen in my days as a plumber, the risk is higher on the residential level.

[ToUtahNow]

Built-in check valves on dishwashers do not supercede local authority codes in the removal of an Air Gap.


The IPC allows a loop to the bottom of the drain board and NO air gap if the dishwasher has it built in.

Mark

[PLUMBER RICK]

the higher end european machines have an automatic check valve built into the water supply. all of the local inspector accept them as designed and approved. they don't require an air gap.

has anyone ever serviced a dishwasher? sure you can get waste water in the machine, but that's what the dishwasher was designed for.

there is a built in air gap on the water fill to the tank. i will try to get a picture today as i have a new one at my shop.

same with a washing machine.

rick.

[NHMaster3015]

Thanks Rick, Good explanation. The codes have gone round and round for years over this issue. I live right on the Maine boarder, a upc state, and they have required the chrome mushroom for years. Homeowners hate it and I can't say I blame them. You put in a thousand dollar Kohler sink and faucet and then stick that ugly assed thing on top. I have honestly in 35 years of plumbing never seen a back flow problem involving a dishwasher. I can see hot it might be possible though.

[plumberscrack]

the higher end european machines have an automatic check valve built into the water supply. all of the local inspector accept them as designed and approved. they don't require an air gap.

has anyone ever serviced a dishwasher? sure you can get waste water in the machine, but that's what the dishwasher was designed for.

there is a built in air gap on the water fill to the tank. i will try to get a picture today as i have a new one at my shop.

same with a washing machine.

rick.
Wait a minute. I thought the main purpose of the air gap was to keep waste water out of the dishwasher and off the clean dinner plate being served to me.

[NHMaster3015]

I think the concern is bacteria migration not so much back water.

[JERRYMAC]

:)
There is many times i have seen kitchen sink flood out the dishwasher,
The airgap is to protect your dish's, But much more important it is to prevent a cross connection between sewer water and the potable water fill valve at the bottom right
corner of most dishwasher's,

JERRYMAC:D

[NHMaster3015]

zounds good to me. He who lives bye the code shall be endowed with many gifts.;)

[westcoastplumber]

I believe jerrymac is right on. The airgap is to keep the clean water from the dirty water.

An airgap is required by the UPC and local jurstictions, it outperforms the high loop allowable by the IPC.

Ugly or not, it is for the safety of not only your potable water system, but others also.

The same with hose bibb vacuum breakers, there isn't really a chance of chemicals going back into the water system from the chemical areators, or from the hose being left in the mud, but it is for everyones protection and should be done with the intent of the code.

[Marti]

You folks are amazing! Thanks for all who contributed.

Does anyone make the cover for that vent in other colors other thamn chrome?

Marti

[oldslowchevy]

what color do you want? also you might want to contact the company who made your faulcet, they mat not only make the color you want but might also make it in a style the matches your faulcet set.

[m a x i m u s]

i am closing on a condo in los angeles, california, and the dishwasher is connected directly to the garbage disposal with no air gap (although the dishwasher outlet line is looped up high in the cabinet). the unit is on an upper floor. i did some research and found that air gaps are required by code in los angeles. can any of the professionals here confirm that finding for me (off the top of your heads, im of course not asking that anyone do physical research).

also, i am relatively handy, and i think that i can install the air gap myself. but how much would you all suggest that i ask as a credit from the seller for this indiscretion? ie, how much do you pro's usually charge for installing an air gap to an existing dishwasher set up?

thanks folks!!!

m

[PLUMBER RICK]

the newer european machines are allowed to drain without an air gap.

but as far as installing an air gap it's pretty simple and basic. unless you don't have a hole in the sink for another opening.

the hole can be drilled and is something an experienced pro should do. especially in a cast iron or pressed steel sink.

as far as cost, or escrow credit. $120.00- $200.00 if a hole is drilled.

where in los angeles are you;)

rick.

[m a x i m u s]

hey, rick. thanks for the info, i appreciate it. it is, in fact, a stainless steel sink, and a hole will need to be drilled (unless i decide to forgo the sprayer, which i don't).

[westcoastplumber]

hey, rick. thanks for the info, i appreciate it. it is, in fact, a stainless steel sink, and a hole will need to be drilled (unless i decide to forgo the sprayer, which i don't).


Why not get a faucet with a pull out sprayer??

Or a single post faucet, with pull out sprayer and a loation or soap dispenser?

You will not need to drill another hole in the sink;)

[m a x i m u s]

Why not get a faucet with a pull out sprayer??

Or a single post faucet, with pull out sprayer and a loation or soap dispenser?

You will not need to drill another hole in the sink;)


i like the faucet thats already on there. also, i want to make it relatively easy, versus spending another $300 on a new faucet, plus install; i just wanted to get the air gap put in for now.

[westcoastplumber]

i like the faucet thats already on there. also, i want to make it relatively easy, versus spending another $300 on a new faucet, plus install; i just wanted to get the air gap put in for now.


Your gonna spend close to that $300 on getting the sink drilled and the new air gap installed, unless you get someone to dril the hole for you, and you install the air gap.


Unless you do both the hole and the gap, then you only have like $100 in material, including the cost of the bit, but, far more invested if you mess the sink up;)