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derobert · Jul 4, 2008, 01:04 AM

Originally Posted by letmetellu

If a doit-yourselfer has a stopped up sink and his friend tells him to fill up the disposal side of the sink with water and stop up the other side of the sink and then turn on the disposal, Where do you suppose the water is going to go, with all of the contaminates that have collected in the disposal and the hose leading from the dishwasher.

I have a confession to make. I can confirm empirically where it goes.

My dishwasher has an air gap.

First, it removes the stopper from the other sink. With a rather impressive force, really. Second, when you get annoyed and hold down the stopper, it unclogs the drain.

At no point does it spew from the air trap. And nor should it — the dishwasher drain inlet is on the suction side (e.g. the same side of the disposal as the sink).

speedball1 · Jul 4, 2008, 04:32 AM

Originally Posted by derobert

I have a confession to make. I can confirm empirically where it goes.

My dishwasher has an air gap.

First, it removes the stopper from the other sink. With a rather impressive force, really. Second, when you get annoyed and hold down the stopper, it unclogs the drain.

At no point does it spew from the air trap. And nor should it — the dishwasher drain inlet is on the suction side (e.g. the same side of the disposal as the sink).

Take another look at a counter top air gap set up,(see image). When it's loaded with water the table of the disposal acts like a centrifugal pump. Water, like electricity. Takes the path of least resistance. Perhaps your clogs are minor ones, with no back pressure resistance, but with most clogs that block a drain the disposal will pump back up to the countertop and alll over your floor. If you go back on our earlier counter air gap complaints you will see that discharging all over the couter top is the main complaint. This is why, in the Tampa Bay Area, that we only use a high loop air gap. In all the five years this site has been up we've never had the first complaint about a high loop air gap going bad. So that would put letmetellu,

Originally Posted by letmetellu, If a doit-yourselfer has a stopped up sink and his friend tells him to fill up the disposal side of the sink with water and stop up the other side of the sink and then turn on the disposal, Where do you suppose the water is going to go, with all of the contaminates that have collected in the disposal and the hose leading from the dishwasher. That's right! Out the air gap!

correct and you in error.
But we thank you for sharing you interesting tail. Cheers, Tom

Milo Dolezal · Jul 4, 2008, 06:45 AM

Air gaps are strictly enforced by plumbing inspectors in So.California. No inspection will pass unless air gap is installed and fully functional.

Here, dishwashers drain into garbage disposer through side outlet. In side inlet of your g/d used to be a knockout plug that your plumber had to remove in order to allow d/w water to enter g/d. Sometimes happens that portion of that plug failed to disengage completely and is now preventing free flow. Do quick inspection for me: Unplug g/d. (unplug g/d). Put your finger inside your g/d and found that opening where d/w water enters g/d. Stick your finger inside. Feel if it is clear. If not, remove rest of the plug.

hkstroud · Jul 4, 2008, 02:24 PM

Daveskee
Are you still around and did you ever get your problem resolved? I recognize that you have replace the air gap but there is something that has bothered me since your original post.

Originally Posted by daveskee

There seems to be to much pressure. So much so that if I take off the metal cover on the air gap, the water shoots up about 8-10" out of the top of the air gap.

Can I take that statement literally?

After removing the chrome cover there should be a dome shaped top or cover over the inlet pipe that directs the water back down toward the drain hose. This would be part of the air gap itself but can be removed. If I take your statement literally, meaning that the water shoots up in the air 8-10, that would mean that the domed top of the air gap would have to be missing. If you mean that the water just shouts out around the air gap that's something else but to shoot UP the top of the air gap has to be missing.

El Glom-o · Jul 6, 2008, 07:43 PM

Originally Posted by hkstroud

Daveskee
Are you still around and did you ever get your problem resolved? I recognize that you have replace the air gap but there is something that has bothered me since your original post.

Can I take that statement literally?

After removing the chrome cover there should be a dome shaped top or cover over the inlet pipe that directs the water back down toward the drain hose. This would be part of the air gap itself but can be removed. If I take your statement literally, meaning that the water shoots up in the air 8-10, that would mean that the domed top of the air gap would have to be missing. If you mean that the water just shouts out around the air gap thats something else but to shoot UP the top of the air gap has to be missing.

I think that daveskee meant that if he takes off the strictly cosmetic chrome cover off his air gap, then removes the cap that is supposed to seal off the air gap and direct the flow of water down towards the drain, he gets the shot of water 8'-10' high, and that if he takes off the chrome cover and leaves the cap in place, he gets the flood of water over his countertop, just like I did.

Well, I followed speedball1's advice. I got rid of the air gap and ran a high loop. The original installers left enough slack in the dishwasher drain hose that I could run the hose just under the countertop. I used an adhesive anchor and a plastic tie-wrap to hold the hose in place under the countertop, and since the original metal trap broke while I was dealing with all of it, I replaced it with a plastic trap that included an internal baffle that directs the hot, detergent-laden, high-pressure discharge from the dishwasher straight down the j-trap, which I believe helps keep it clear. Filled the hole in the sink surround with a soap dispenser and have had no problems at all with the dishwasher or sink drain.

afaroo · Jul 6, 2008, 09:01 PM

I found this link in California city code web site,I am not that experens in like Tom,Bob and Milo, I am just here to learn from you guys please don't get mad if post some time, Thanks to All.

Best Regards,
John

Dishwasher Air Gap - InterNACHI Message Board

Milo Dolezal · Jul 6, 2008, 09:16 PM

Afaroo: Thanks for posting the Inspectors Blog link. I see, the responses vary. It confirms that Plumbing Codes are differ from State to State. Inspector from CA (Santa Clarita) confirmed that Air Gap is required in my area. That's why it is important that people publish their location so they can get more accurate answer to their plumbing problem.

speedball1 · Jul 7, 2008, 06:00 AM

Well, I followed speedball1's advice. I got rid of the air gap and ran a high loop. The original installers left enough slack in the dishwasher drain hose that I could run the hose just under the countertop. Filled the hole in the sink surround with a soap dispenser and have had no problems at all with the dishwasher or sink drain.

I REST MY CASE!! Natural applications, such as a high loop or a vent through the roof will out last, will give less problems and will give you less service calls then mechanical applications such as a counter top air gap or a Air Admittance Valve. This is exactly what I've been saying since day one. Regards, Tom

uncledewey · Sep 13, 2008, 09:08 AM

I will be installing a granite countertop with an under the countertop sink. Thus, if water comes out of the air gap it will flow on the countertop and in my case will flow off the granite that abuts my pass through to the dining room and on to my wood floors. So I have two questions: 1) Are there air gaps that have a "spout" that will direct the water to the sink?; 2) Also if I do not use the air gap and place my dishwasher drain hose looped high can I also place a check valve in the hose to prevent any water going back into my dishwasher? Our city code requires a air gap even if there is a built in air gap in the dishwasher.

We have used our dishwasher since 1998 without a problem. We also rinse our dishes prior to placing in the dishwasher.

A perplexed homeowner, Uncle Dewey

speedball1 · Sep 13, 2008, 05:21 PM

Hey Uncle!

1) Are there air gaps that have a "spout" that will direct the water to the sink?;

Nope!

2) Also if I do not use the air gap and place my dishwasher drain hose looped high can I also place a check valve in the hose to prevent any water going back into my dishwasher?

Sure can! You do realize that the dishwasher has a sump that collects the liquid left in the hose when the pump shuts down whether you have a high loop or a counter top air gap don't you? But if you wish to install a check valve so it doesn't drain back into the sump that's cool too. Good luck, Tom

uncledewey · Sep 15, 2008, 10:43 AM

Hi Again,

I hadn't thought about it, but it is logical that the pump would not get all of the water into the drain from the dishwasher and would retain some water between usage. I have made some other conclusions from reading this forum which may be right or wrong! I have concluded that the real purpose of the air gap is to direct water away from the dishwasher into the sink when there is a problem with the disposal/sink drain. Also, if the dishwasher drain is looped high to the underside of the countertop then there is little likelihood that the water would ever drain back into the dishwasher.

Is my thinking correct? Sorry to be a bother. Uncle Dewey

PS: My neighbor had granite countertop installed and their plumber told them they did not need the air gap. d

speedball1 · Sep 15, 2008, 12:31 PM

You're no bother Dewey,
That's why we're here.

I have concluded that the real purpose of the air gap is to direct water away from the dishwasher into the sink when there is a problem with the disposal/sink drain.

Almost but not quite! The discharge hose directs the water from the diswasher to the sink while a air gap, ( loop or counter top) provides a interval (gap) in the hose to prevent any back siphonage from the disposal or the sink back to the dish washer.

if the dishwasher drain is looped high to the underside of the countertop then there is little likelihood that the water would ever drain back into the dishwasher.

True! The very top bend of the hose is the air gap and nothing from the sink or disposal can drain past it back into the DW.
Egards, tom

uncledewey · Sep 15, 2008, 12:41 PM

Geez. What a stupid way to prevent siphonage. We had a device on our outside hose faucet to prevent water being siphoned back onto the water system. I got rid of it as it only caused problems with leakage, etc.

I'm going to get rid of the air gap!! :) Uncle Dewey

speedball1 · Sep 15, 2008, 12:49 PM

Originally Posted by uncledewey

Geez. What a stupid way to prevent siphonage. We had a device on our outside hose faucet to prevent water being siphoned back onto the water system. I got rid of it as it only caused problems with leakage, etc.

I'm going to get rid of the air gap!!!!!!!!!! :) Uncle Dewey

BAD IDEA!! The air gap's necessary to prevent all the garbage in the disposal from draining back into the dishwasher.. No matter which one you choose you have to have one or the other installed. Your backflow preventer on the hose bib's not the same thing. Regards, Tom

uncledewey · Sep 15, 2008, 02:25 PM

Hi Again,

When reading the original question about water spewing out of the air gap, another problem/solution might be the problem we had in our townhome complex. Washing machine hoses were leaking and in my conversations with one owner they mentioned the insurance agent had measured 180 PSI of water pressure, so they replaced their water pressure control valve. With some investigation I found that the maximum water pressure in a home is 80 PSI. I measured mine and found it would increase to 150 PSI. Then I learned that if you empty your water heater (three showers, a tub of clothes, etc.) that the water heater will need to heat all of that cold water and guess what--heating water causes it to expand. Our homes did not have the solution which is a pressure relief tank (I think that is the name) so we replaced all of our pressure control valves and added the pressure relief tank. Could it be the problem with water spewing out of the air gap is caused by too high water pressure?

Just thinking, Uncle Dewey

speedball1 · Sep 15, 2008, 03:41 PM

Dewey,
When did we stop talking about air gaps and began to dive into excessive house pressure? The average house PSI is 45 PSI to 60 PSI.( That's why water towers are 100 feet high). Anything over that PSI will place a strain on joints, valves and faucets. I hope I've talked you out of doing away with a dishwasher air gap. A air gap's as necessary to a dishwasher as a water supply.

Could it be the problem with water spewing out of the air gap is caused by too high water pressure?

The house water pressure has nothing whatsoever to do with a air gap. The DW pump determines how much pressure the DW discharges. The reason a counter top air gap "spews" water out all over is a chunk of food blocks up in the small tube in the air gap preventing the discharge from getting to the disposal. Since the high loop hose hasn't got a small aperture for food to hang up in this will never happen. Regards, Tom

Artemus · Oct 4, 2008, 05:03 PM

Talk about not seeing the forest for the trees. While everyone is arguing which is better, an air gap or a loop, TSAINTA (Post #40) had it right. I was having the same problem with my newly replaced air gap and by positioning the two vent holes on the plastic cap over the discharge side of the divider, the water stopped spewing out of the chrome cover. Kudos to TSAINTA.

speedball1 · Oct 5, 2008, 07:17 AM

Originally Posted by Artemus

Talk about not seeing the forest for the trees. While everyone is arguing which is better, an air gap or a loop, TSAINTA (Post #40) had it right. I was having the same problem with my newly replaced air gap and by positioning the two vent holes on the plastic cap over the discharge side of the divider, the water stopped spewing out of the chrome cover. Kudos to TSAINTA.

Art, You had a installation problem with your counter top air gap. Glad you found your problem but we weren't discussing a problem installing a air gap were we? Dave had a problem with the counter top air gap spewing water all over his counter top. He tried three air gaps with no improvement. He finally removed the counter top air gap, replaced it with a soap dispenser and ran a high loop air gap.
Problem soloved! No more spills! May I repeat my earlier convictions.

Natural applications, such as a high loop or a vent through the roof will out last, will give less problems and will give you less service calls then mechanical applications such as a counter top air gap or a Air Admittance Valve. This is exactly what I've been saying since day one.

Regards, Tom

nakedbichon · Oct 5, 2008, 11:38 AM

TSAINTA fixed my early morning problem. We just moved into a rental home ran the dishwasher and were greeted with a waterfall out of the airgap. I checked it etc, and put the top plug back just like it was, with one tube on each side. After TSAINTA's suggestion, problem solved. THANKS!

speedball1 · Oct 5, 2008, 12:26 PM

Kudos to TSAINTA for coming up with a solution. This should be required reading for air gap installation problems and well worth the time to study it. However, common sense dictates that a mechanical application will fail while a natural application will not.
We don't install counter top air gaps in my area for two reasons.
1) Cosmetics, Some homeowners don't want a air gap sticking up out of their brand new stone or slate counter top.
2) The rate of countertop air gap failures as per against high loop ones.
TSAINTA took the mystery out of some of the problems that counter top air gaps run into upon installation and for that the Plumbing Page thanks you. Thank you TSAINTA! Regards, Tom