I have had the usual symptomatic water overflow out of the dishwasher air gap on the top of my sink countertop. After replacing the countertop with granite and relocating the air gap hole, I replaced the hose from the air gap to the disposal and insured there was no blockage in the disposal and new hose. Yet I have so much water pressure coming from the dishwasher that it shoots out of the air gap vent. I confirm the water is draining into the disposal from the air gap vent but it seems there is so much water or the pressure is so great the system can't handle the amount of water being discharged and backs up into the air gap. I've even looped the extra amount of hose from the dishwasher to the air gap above the disposal drain height to see if that would solve this. It did seem to take some of the pressure off the water coming out of the air gap but it still spews out. After searching and reading all the posts regarding this usually common issue, I'm at a loss. Anyone have any ideas?

Speedball1, our resident plumber, tells us he never uses air gaps nor do I. They are intended to prevent back siphoning but you can do the same with a high loop in the drain hose. Run the drain out of the washer all the way to just under the counter and strap it to the cabinet, then to your disposal. The problem you are experiencing should not happen but we don't know if you added a new washer or who did your plumbing. Something's is causing a partial blockage, you did not accidentally reverse the two hoses did you? The drain from the machine goes to the smaller of the two tubes of the air gap.

Ok I just conducted a little experiment and now I have no idea what the problem is. I disconnected the large hose at the disposal so that it was still connected to the air gap vent. I put the unattached end into a bucket and started the dishwasher. When the dishwasher drained water and water came out of the larger hose unobstructed into the bucket, water still came out of the air gap vent, same as before!

Is it possible that the dishwasher is draining with too much pressure?

Dish washer pressure can't get stronger than day1. It is the same dishwasher, right? The hose leading to the air gap from the machine should be nearly straight, no loop so cut it shorter. Is the air gap the original or did you replace it when the counters went in? There is a very slim chance that you have a bad air gap. They are so simple the chances are slim. I'd remove it and just strap the drain I described earlier in the post. They are a pain and Speedball1 says they aren't needed although some cities require them to be up to code.

Haven't changed dishwasher. Same as when we moved in, but we were having this issue then too. I've replaced the original air gap with two new ones, the first the same style and the second a different style. Same result each time.

Hopefully someone might have an idea. I'd like to try and keep it up to code by keeping the air gap.

So you've had this issue all along, not tied to the new counters. Do you know that your city building code requires a gap? Dave, code is for construction and you doing a DIY have a bit of latitude, take it out.

Yes local code here requires the air gap. If I was staying in the house I'd solve it with your solution but we're preping to sell soon and it'll have to pass inspection so I'd rather take care of it per code. I also want to know for my own education why it's happening.

So if there's anyone else out there with any ideas, let me know! Thanks in advance.

Yes local code here requires the air gap. If I was staying in the house I'd solve it with your solution but we're preping to sell soon and it'll have to pass inspection so I'd rather take care of it per code. I also want to know for my own education why it's happening.

So if there's anyone else out there with any ideas, let me know! Thanks in advance.

Are there any kinks in the 7/8" hose going into the disposal?

Are you using the correct inlets and outlets on the air-gap?

The smaller inlet takes the hose from the dishwasher and the larger outlet gets the hose going into the disposal.

Also, check the inlet on the disposal to be sure the plug has been completely removed.

Growler's correct about checking the disposals knock out plug, seen many still partially attached. However you said it still happens when you put the discharge hoes into a bucket. Since it was a new hose I'm stumped on this problem. Before we yell uncle please double check the two hoses going to the air gap. Growler and I both mentioned the smaller hose goes between the washer and the air gap. Sorry I could not solve this issue Dave.

There are no kinks in the 7/8" hose and the correct outlets on the air gap are hooked up correctly. Small inlet from the dishwasher and larger outlet to the disposal. Knockout plug is not present as I've reached into the disposal and felt the open hole with my finger. I've even put a small screwdriver into the inlet and it came through into the disposal freely. I even felt the water shooting into the disposal from the 7/8" hose inlet as the dishwasher drained. But listen to this, as the water is shooting into the disposal as it should, water is still coming out of the air gap! There seems to be too 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.

As far as I know, you can't regulate the drainage pressure from the dishwasher.

Could a blockage in the dishwasher or dishwasher drainage line cause increased pressure? I assume it would just do the opposite and cause less water pressure.

Thanks for the tips guys but I think I've thought of everything that's been suggested so far. I can't believe no one else has had this problem. Well I'm holding out hope that this thing won't beat me and am still open to suggestions if there are any others out there!

Speedball1, our resident plumber, tells us he never uses air gaps nor do I. They are intended to prevent back siphoning but you can do the same with a high loop in the drain hose. Run the drain out of the washer all the way to just under the counter and strap it to the cabinet, then to your disposal. The problem you are experiencing should not happen but we don't know if you added a new washer or who did your plumbing. Somethings is causing a partial blockage, you did not accidently reverse the two hoses did you? The drain from the machine goes to the smaller of the two tubes of the air gap.

In our code book we have to install an air gap, and I do not agree with the notion that you don't need one to prevent back flow into the dishwasher. 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 had the usual symptomatic water overflow out of the dishwasher air gap on the top of my sink countertop. After replacing the countertop with granite and relocating the air gap hole, I replaced the hose from the air gap to the disposal and insured there was no blockage in the disposal and new hose. Yet I have so much water pressure coming from the dishwasher that it shoots out of the air gap vent. I confirm the water is draining into the disposal from the air gap vent but it seems there is so much water or the pressure is so great the system can't handle the amount of water being discharged and backs up into the air gap. I've even looped the extra amount of hose from the dishwasher to the air gap above the disposal drain height to see if that would solve this. It did seem to take some of the pressure off of the water coming out of the air gap but it still spews out. After searching and reading all the posts regarding this usually common issue, I'm at a loss. Anyone have any ideas?

After all of the things that you have tried I think I would go to the hardware store and invest in a new air gap, they come in different designs and it could be that there is a problem with your's and a new one might stop the problem.

One thing I will mention but I am sure that you have checked is to make sure that there is not kink in the 7'8 inch hose from the air gap to the disposal, also make sure that the 7/8 inch hose has a downward slope all the way to the disposal.

I've replaced the old air gap with two different types and same result. No kink and the 7/8" hose is downward sloped. Already addressed these. Any other ideas?

Sorry Dave but I've run out of ideas and it isn't feasible to swap out a dishwasher to try another. Seems like you've done everything else. I'm sure the dishwasher people won't like this idea but you could try reducing the drain tube between the machine and the air gap. Try partially crushing the drain hose with a C clamp to see if it fixes your problem and doesn't create a new one.

In our code book we have to install an air gap, and I do not agree with the notion that you don't need one to prevent back flow into the dishwasher. 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.

"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 a air-gap it's going to go all over the counter top and kitchen floor. That's where.
And what idiot would advise anyone to pour more water in a clogged sink and then attempt to use a disposal to clear the clog. I have been putting in dishwashers in condos and new houses since 1979 using a high loop instead if counter top air gap. In all those years, and in the hundreds of installations we have done, we haven't had even one complaint about a high loop misfunctioning.
I KNOW that the air-gaps can't make that statement because we get complaints about counter top floods from time to time here in the plumbing page.
LetmetellU, perhaps you and Growler are forced, by code, to use counter top air-gaps but here we have a classic case of mechanical versus natural. Sort of like "What is more likely to fail?" A regular vent out the roof or a AAV?
A high loop or a counter top air-gap? In my area we have a choice. We went with a high loop. I rest my case. Tom

"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 a air-gap it's going to go all over the counter top and kitchen floor.

Sure -- And without the air gap it's going to go right into the hose and then down the hose and contaminate the dishwasher.

I hate to break it to you, Tom, but your reply was almost verbatim the example I give during class for why an air-gap is required under the UPC.

I'm not going to get into a pissing match with you over which code is superior over the other, but I think it should be noted that it was you who illustrated the point.


And what idiot would advise anyone to pour more water in a clogged sink and then attempt to use a disposal to clear the clog.

You're kidding, right?

Think back on all of the truly bad advice you've left negative feedback on, Tom.


I have been putting in dishwashers in condos and new houses since 1979 using a high loop instead if counter top air gap. In all those years, and in the hundreds of installations we have done, we haven't had even one complaint about a high loop misfunctioning.
I KNOW that the air-gaps can't make that statement because we get complaints about counter top floods from time to time here in the plumbing page.

Y'know, I've yet to encounter the situation you describe in a properly installed air gap.

Usually if the air gap has failed, it is because the user failed to rinse the dishes off or the limiter on the discharge pump has failed.


LetmetellU, perhaps you and Growler are forced, by code, to use counter top air-gaps but here we have a classic case of mechanical versus natural. Sort of like "What is more likely to fail?" A regular vent out the roof or a AAV?
A high loop or a counter top air-gap? In my area we have a choice. We went with a high loop. I rest my case. Tom

Sure -- But your example contaminated the dishwasher and the dishes in the dishwasher (something the user couldn't possibly be aware of), while the other example merely flooded the counter top and kitchen floor (the user would have to be deaf, dumb and blind to not figure out there was a problem if this should happen).

Great rebuttal Growler. Good points all! One problem. Would you care to check back on the complaints we have got on air-gaps versus high loops? Gee! That's correct! We haven't got any high loop complaints have we? You're correct about the disposal pumping gray water back into the dishwasher if some fool were to advise clearing a clogged drain line by filling up the sink with water and turning on the disposal. Let's see how many complainbts we have got over the years on that scenario. Oops! Can''t find any of those either. Even if the drain line were cloggec and standing water in the tub it still wouldn't drain back into the DW unless some total idiot ran the disposal. I can only repeat, "here we have a classic case of mechanical versus natural. Sort of like "What is more likely to fail?" A regular vent out the roof or a AAV?
A high loop or a counter top air-gap?, (This is a no brainer) In my area we have a choice. We went with a high loop. I rest my case."
I was impressed. While your rebuttal was great and you took it point by point the very complaints and posts by askers prove that while your concerns and arguments sound valid they don't hold up when you check back on askers complaints of the same nature. However, I enjoyed your reply. Have a great week end ! Tom

I think that anyone that would call the water in a stopped up disposal, the nastiest household fixture in the entire house, even nastier than the commode, gray water is an idiot.

First of all thanks for calling me a idiot. Now, just what's the discharge from tubs, showers, lavatories, washers and kiutchen sinks called? Gee! Whadda you know! It's called "gray water" as per against "fecal matter". I would be most interested in your name for it. In the meantime if you're going to insult someone and call him a idiot get your definitions correct before you do it or you might end up looking like one yourself.

Perhaps whoever coined the term ''gray water'' for the discharge from sinks, showers, etc. was an idiot, but it is a common term for it. I wouldn't call a highly trained, experienced professional an idiot for using a common term. Those that persist on calling people idiots on AMHD can become former members.

I like the idea of restricting the flow from the dishwasher. It would have been my first suggestion. The C-clamp will be a good first try. Before selling the house, you may want to put something inside the hose or pump outlet out of view. I never have posted much to plumbing because when I came here, Tom was posting better answers than I could.

You do want to fix it. In many cases a problem is still yours after you sell the house.

Would you care to check back on the complaints we have got on air-gaps versus high loops? Gee! That's correct! We haven't got any high loop complaints have we?

Well, given the nature of the failure of a high loop should it fail, no one is going to notice.

Do you check your dishwasher to see if there is any contaminated water sitting in the bottom of it? Not that you would know it was contaminated, of course.


You're correct about the disposal pumping gray water back into the dishwasher if some fool were to advise clearing a clogged drain line by filling up the sink with water and turning on the disposal. Let's see how many complainbts we have got over the years on that scenario. Oops! Can''t find any of those either.

And what if there was a partial clog in the discharge line?

Some of the waste water would pump past the blockage, but most of it would gravity drain back into the dishwashers sump.

And also, we're talking about connecting the drain hose to the disposal.

Most Plumbers I know rough in a kitchen drain with a partition cross and pipe the discharge hose into a separate trap -- Without the air gap as a tell-tale, how would you even know a problem exists with a high loop?

The discharged water certainly isn't going to back up into the sink if the discharge hose is plugged or partially plugged.

I wouldn't call a highly trained, experienced professional an idiot for using a common term.

No?

Yet you have no problem with disagreeing mightily and vociferously with 'highly trained, experienced professionals' such as myself, Labman.

"Well, given the nature of the failure of a high loop should it fail, no one is going to notice.
Do you check your dishwasher to see if there is any contaminated water sitting in the bottom of it? Not that you would know it was contaminated, of course."

If a higfh loop fails you won't have to check the sump to find out.
Simply open the door and all the water that was used will come gushing out.
However, That's never happened in all the dishwashers my company's installed or has it ever been a complaint here in the [plumbing page.

"And also, we're talking about connecting the drain hose to the disposal."
Most Plumbers I know rough in a kitchen drain with a partition cross and pipe the discharge hose into a separate trap -"

we don't complicate things in my area, We connect to the disposal and if there's no disposal we connect to a branch tailpiece.

-" Without the air gap as a tell-tale, how would you even know a problem exists with a high loop?"

This question has been answered earlier. You'd have a flood the moment you opened the dishwasher door.

Dave, you got to problem with your air -gap? Run a high loop and forget it.
Regards, Tom

I would normally be out of this by now because we've got some great pros in discussion. Dave did you ever try my suggestion about restricting the discharge? Since you seem to want to keep the air gap (don't do it) you could throttle down the volume of your dishwasher power drain.

First of all thanks for calling me a idiot. Now, just what's the discharge from tubs, showers, lavatories, washers and kiutchen sinks called? Gee! Whadda ya know! It's called "gray water" as per against "fecal matter". I would be most interested in your name for it. In the meantime if you're gonna insult someone and call him a idiot get your definitions correct before you do it or you might end up looking like one yourself.

I have reread all of the post that I have posted on this subject and I can not find where I called any individual, by name or by suggestion, an Idiot. All I was trying to do was make a point about how nasty the water is that goes through a disposal.

Usually if the air gap has failed, it is because the user failed to rinse the dishes off or the limiter on the discharge pump has failed.


I'm not sure what the limiter on the discharge pump is but is that something that the original poster should look at?

I haven't tried restricting the drain hose yet but that's my next step. I'll post the results when I'm done. Thanks for all the input.

Last suggestion Dave,

This shouldn't be a question about what's better, a air-gap or a high loop, this should be about what works for you. You've fought your air-gap about as far as you can take it. Choking or restricting the discharge by clamping the hose is a last ditch effort and will set up back pressure in the pump. I don't know if this will be harmful to the unit or not since we have never been faced with your problemin in our area but I do know restricting the discharge of anything can't be beneficial.
If everything else fails with your air-gap then remove it, place a chrome cock hole cover or a soap dispenser in its place and run a high loop on the discharge hose. Run the loop as high as it will go under the cabinet and secure it with a pipe strap,(see image) and put this all behind you. This is not to say the other "pro air-gap" experts are wrong. This is about getting your problem solved in the fastest, easiest way and I believe a high loop may be the answer. Good luck, Tom

Hear, hear Speedball. Codes are important, don't get me wrong, but they are not absolute physical laws. At the time my home was built air gaps were not required but they are now. Its just a new law to avoid worst case scenarios not the day to day issue. Where I live drywall was not code until 1975, does that mean it was unsafe? Some codes are driven by lobby groups and unions and are not necessarily mandated by physical laws. Many DIY repairs are not always code but improvisation is sometimes needed when the original up to code part fails.

Hear, hear Speedball. Codes are important, don't get me wrong, but they are not absolute physical laws.

I'm reminded of the arguments I've had with architects, designers and homeowners over the years:

'But Plumbing Codes are arbitrary and they certainly don't apply to me'.

My usual pat response is, "They most certainly are not arbitrary and they most definitely do apply to you."

Period.

Quite frankly, I'm appalled by yours and Tom's answers to this problem, Dave.

If he lived in the 90% of the country where high loops are accepted, then I wouldn't have word one to say on the subject -- But to advise someone to defy the prevailing code in their community is just wrong.

Period.


At the time my home was built air gaps were not required but they are now.

I don't know if you're still out in the field or not, but the old policy of 'Grandfathering' in older installations that are no longer up to code is a thing of the past -- The general consensus is that if you open it up (expose it to view), you must bring it up to code.

Period.


Its just a new law to avoid worst case scenarios not the day to day issue.

It isn't, actually.

If you read the code book Tom is operating from -- A "highloop" is an acceptable alternative (under the IPC and the SPC) to an approved airgap -- Meaning that an airgap is an additional accepted alternative.

Most high end Plumbers in jurisdictions covered by the IPC and the SPC opt for counter mounted airgaps or Johnson Tee's -- In the unwritten rules of Plumbing, 'Cover Thine Own Butt' is in the top 5.


Many DIY repairs are not always code but improvisation is sometimes needed when the original up to code part fails.

Wrong.

It isn't the code that has failed -- It is something in either the installation or the appliance that has failed.

Tom has stated that there are a number of posts regarding the failure of counter mounted airgaps -- I'm not going to dispute this, because I can visualize installation snafu's where this might occur, but in over twenty years of owning and running a Plumbing company, I have never once had this happen to any of my installations.

Growler, Growler, Growler,

The problem with you younger, "by the book" plumbers is that the "book" never tought you to improvise or think outside the box. Everythings black and white to you. "If it ain't code, it ain't right". You appear to worry more about code then you do about results. Did you even take the time to read my last post. Let's get Daves dishwasher workingt for him and quit
Hassling about the pros-and cons of air-gaps. He's tried three air-gaps with the same result. I gave him a solution. Do you have anything better??

Pumps have a pressure/volume curve. If you increase the back pressure by using a restriction, the volume delivered will decrease. It is easier to destroy a pump with too low of back pressure than too high. Try the C-clamp. If it works, go to something more permanent. Even a partial kink in the hose might do. Keep it out of sight so nobody fixes it. If I were going to live in the house, I would have a high loop installed long before this. When you sell it, it may be inspected and you may be presented with the bill to fix all the code violations.

I point out mistakes, which upsets some people when a non plumber catches theirs, but don't call people idiots here.

I might just have cleared up the mystery of why his air-gap clogs up.
I went over to the appliance page and picked some brains. It seems that mid and upper level dishwashers have grinders that grind the food up so it won't clog a air-gap. The lower end ones use the pump to grind the food particles. If Dave had a faulty grinder or didn't wash the plates good this could be the reason. This is not a solution, ( I gave that in a earlier post) but just one possible explanation. Regards, tom

I don't understand how a faulty grinder or pump would result in the increase in water pressure draining from the dishwasher. Speedball1, could you explain that to this novice?

I don't understand how a faulty grinder or pump would result in the increase in water pressure draining from the dishwasher. Speedball1, could you explain that to this novice?

Sorry Dave, My bad! In the confusion over which was the best, air-gap or high loop, I lost track of your original complaint and was thinking the air-gap overflowed due to blockage in the dischage. I apologize for my error. However, there have been only two solutions offered. One was to choke down on the volume entering the air-gap and I'll repeat mine. If everything else fails with your air-gap then remove it, place a chrome cock hole cover or a soap dispenser in its place and run a high loop on the discharge hose. Run the loop as high as it will go under the cabinet and secure it with a pipe strap,(see image) and put this all behind you. This is not to say the other "pro air-gap" experts are wrong. This is about getting your problem solved in the fastest, easiest way and I believe a high loop may be the answer.
If restricting the flow to the air-gap doesn't help I would give some serious thought to my solution. Anyway you go I wish you the best of luck. Tom.

I found this web site while trying to find help with the very same problem described by daveskee. Did he ever get his trouble resolved?

It looks to me like the air gap that came with my dishwasher is just a poor design that doesn't have a chance of properly draining the water at the kind of pressure and volume as delivered by the dishwasher pump. I tried looking at replacements on-line but all of the photos show them with decorative covers in place so I can't see if the gap itself looks any better than the one I have. Also, daveskee mentioned going through several replacements without success, so I'm thinking that these air gaps are all pretty similar and replacing mine probably wouldn't solve anything. But does anyone have a suggestion for a particular model, should I decide to go that way?

I've found the air gap/high loop controversy interesting. I don't know what the Baltimore City code says about them.

Thank you.

I have had the usual symptomatic water overflow out of the dishwasher air gap on the top of my sink countertop. After replacing the countertop with granite and relocating the air gap hole, I replaced the hose from the air gap to the disposal and insured there was no blockage in the disposal and new hose. Yet I have so much water pressure coming from the dishwasher that it shoots out of the air gap vent. I confirm the water is draining into the disposal from the air gap vent but it seems there is so much water or the pressure is so great the system can't handle the amount of water being discharged and backs up into the air gap. I've even looped the extra amount of hose from the dishwasher to the air gap above the disposal drain height to see if that would solve this. It did seem to take some of the pressure off of the water coming out of the air gap but it still spews out. After searching and reading all the posts regarding this usually common issue, I'm at a loss. Anyone have any ideas?

Just a guess but some times small chicken bones or tooth picks can get stuck in the dishwasher discharge hose. They are to long to turn the corner in the air gap but can fall back down the hose and out of sight, then come right back up and plug a new air gap.

If you pop the top off the air gap and remove the top plug. With the dishwasher set on discharge … close the door on the dish washer for about one second... what ever is in the hose will come out the top of the air gap. Put it back together and test it.

Just an old handyman but I have seen it three or four times over the years.

Happy trails
Mark

I'm thinking that these air gaps are all pretty similar and replacing mine probably wouldn't solve anything. But does anyone have a suggestion for a particular model, should I decide to go that way?
ElGlom-0, I have a solution for you that has worked without complaints or call backs in my area for years. Remove the old air gap and install a chrome cock hole cover in its place. Now run a high loop air gap by replacing the discharge hose and looping it up as high as it will go in the cabinet and securing it with a pipe strap 0or band iron. You may now connect to the disposal and forgrt about any more counter top back ups. Good luck, Tom

I have read the lengthy and heated answers and comments to this question.

I have just returned from a client who has a Jen-Air DishWasher that "smells like dirty water".
I am having the same problem as Daveskee and El Glam-O.

The installation of an air-gap allows water to erupt from the air-gap during the pump/drain cycle of the DW. And, sorry Speedball1, but draining a sink-full of water from the single-basin sink with disposal (prior to air-gap installation) allows water to return up the DW drain line and back into the disposal. This may well be due to a plumbing vent problem "downstream" from the disposal, but regardless, it seems physically impossible for this to happen.

I agree with Daveskee that the problem does indeed seem to be that the DW pumps water too fast.. . at least faster than the hose downstream from the air gap can allow to pass.

Please, any suggestions or further insight into how to remedy the situation would be greatly appreciated by myself, Daveskee, El Glam-O, and the hot Russian MILF who needs me to fix her DW.

And please, Daveskee and I have both made certain that the drain lines are clear and un-kinked, the air-gaps are clean and/or new, the disposal KO has been KO'd etc, etc.

To daveskee: As a person who has remodeled and sold and repaired, I'd suggest you swallow the moral dilemma and go with Speedball1's answer: high-loop, hide the loop, and wait for the home inspection team to complain. If they do, offer the buyer the $ for the repair and nothing more. This "interesting puzzler" could cost you a sale.

Thanks for reading. I'll be interested in any further brainstorming.

Here's something (yet another thing) I learned by screwing up and messing around until I finally got it right. In the top of an air gap is an insert with two holes. Inside the air gap are two divisions. One division connects to the inflow side of the air gap (from the dishwasher) and the other connects to the outflow side (to the disposal). If the top insert is put in wrong, water will flow from it when the dishwasher empties. For correct operation of the air gap both holes in the insert need to be positioned over the outflow division of the air gap.

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).

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

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.

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.

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.

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.

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 (http://www.nachi.org/forum/showthread.php?t=8491)

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.

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

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

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

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

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

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

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

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

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

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.

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

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!

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

Is it possible that you also installed a new garbage disposal when you added the granite? If so I suspect you did not knock out the plug in the air gap Garbage disposal line. You just take a long screw driver and insert it into the Garbage disposal air gap return line orifice and hammer out the plug. The plug will end up inside the disposal where you can retrieve and dispose of it.

After that I think your mystery air gap issue will disappear.

Or, you may have a kink in the 7/8" hose (connects air gap and garbage disposer ). Also, remove trim from air gap and make sure the actual tip of air gap is installed properly.

Barny, Milo,
Do you guys realize you're responding to the last post of a year old? Barny, how did you get involved in answering a thread thnay was posted over two years ago. Inquiring minds want to know! Tom

Speedball1 - I actually have this site saved on my lap top to show clients the controversy with air gaps and why I also recommend the loop method- in 20+ years I have never had a complaint with a loop, but with air gaps... at least 40% of installs. I asked a friend who is a mechanical engineer about air gaps and this is his response- poor design! "The air gap was designed in the mid '50's when DW pumps were as efficient as my Dad's Buick Roadmaster. Today's pumps are far more efficient - hence today's DW uses about 30% of the volume of water as a unit 20 years old. Higher efficiency comes with higher pressure and frequently air gaps cannot handle it. Any slight obstruction- food, hair, toothpicks etc. will cause backpressure and viola! out the air gap it goes!" No one ever maintains their air gaps, checking for obstructions etc until water starts pouring into the sink or onto the counter tops. I am sure that over the years you have worked on AG systems only to find food/sludge/gunk built up on the discharge side of the AG and thus causing overflows. Maybe it is time to reinvent/redesign the Air Gap! They look prettier, but they still cause the same problems.

Damm! I think I'm in love! Are you listening Growler and all you UPC guys that think a counter top air gap out performs a high loop? CSI! Thank ya-Thank ya-thank you!!
Cheeers, Tom

Damm! I think I'm in love!! Are ya listening Growler and all you UPC guys that think a counter top air gap out performs a high loop?? CSI! Thank ya-Thank ya-thank ya!!!
Cheeers, Tom

No one, including myself, has ever claimed a 'counter mounted air-gap out performs a high loop' -- Our argument has always been that it is an issue of code compliance.

We do not get to pick which sections of the code we will be in compliance with, Tom -- It's as simple as that.

TSainta, I'm having a similary problem, but can't follow your explanation. I pulled the insert and see the small inlet hose and larger outlet hole across from it. To either side of these two holes are discharge ports. It looks like water would come out of the Dishwasher Pump, spray onto the bottom of the insert, and in threory be redirected to the drain. I believe it just sprays off the bottom of the insert and spreads out; some goes down the drain and some comes out the main overflow to the sink, and some comes out from the bottom of cover. I did not see anything dividing the area. Can you send me a picture or something similar? Also, are the two interior ports supposed to pointed in a particular direction such as towards the Cover vent and ultimately towards the sink?

Mikirker,
. In the top of an air gap is an insert with two holes. Inside the air gap are two divisions. One division connects to the inflow side of the air gap (from the dishwasher) and the other connects to the outflow side (to the disposal). If the top insert is put in wrong, water will flow from it when the dishwasher empties. For correct operation of the air gap both holes in the insert need to be positioned over the outflow division of the air gap.


In case you ever want to do away with that pesky counter top air gap and install a high loop Air gap.(see image) I'll be more then happy to help.
Note: In all the hundreds of high loop air gaps that my company's installed we have yet to get our first complaint or service call. This holds true in the high loops that we have advised installing on The Plumbing Page right here.

Growler; Don't be so touchy! I was just having some fun. We are allowed to have fun doing this aren't we? Cheers, Tom

Growler; Don't be so touchy! I was just having some fun.

You might call misrepresenting what I said "fun", but most anybody else would call it 'lying in your teeth'.

You might call misrepresenting what I said "fun", but most anybody else would call it 'lying in your teeth'.

Then we're in agreement. High loops rule! Say it!

Growler, what is the deal with the cat picture? Just curious.

I have this problem too. I had to change the old hose from the air gap to the disposal with a longer one because my new undermount soap dispenser was getting in the way of the old hose. I have a much longer hose now and water shoots out the air gap. I'm thinking that the longer hose has created more resistance at the air gap, resulting in water discharge. Haven't tried to shorten the hose yet.

Photoman: Make sure that that hose is :

1. Not kinked and/or flattened and that is has long, continuous loop
2. is 7/8" in diameter
3. you removed plug from gargage disposer inlet
4. there is no obstruction in garbage disposal inlet
5. air gap cap is put in the right way ( applies only to some air gaps )
6. hose should slope from air gap towards garbage disposal

Everything you've described... put me down also. I've taken everything apart and cleaned. Put it back and water
Still shoots out top of gap while also draining what it can into the disposal. The gap mechanism is clean and undamaged.
I'm about ready to just put the damned drain hose right into the disposal like the first guy said

OK, I solved my problem. Since your description so closely matched mine.. I'm posting this. The last thing I had to do was PUT THE SMALL
SCREW ON CAP BENEATH THE LARGER CAP BACK ON. That stopped the water flying out of the unit... but here's what I did:

1. Remove the air gap. Unscrew cover and retainer from top and pull it down under the sink.
2. Take the drain hose to disposal off. Run your garden hose through it and clean it out good. Make sure
Water runs easily through and no kinks.
3. Do the same with the plastic air gap. Clean it with the hose also.
4. Put it all back as before. Do make sure the disposal plug is knocked out beneath the drain hose. Clean
All of the fittings well leaving no debris. Put the small screw on cap back.
5. Put your dishwasher on 'rinse' for a minute or so, then cancel it to let it drain and see if you fixed it. If you
Don't have the 'cancel' feature-you'd have to let it go through a cycle to drain... Water
Should be flying into the disposal. I had NONE out the top... woo hoo.

I'm about ready to just put the damned drain hose right into the disposal like the first guy said
And I'm thinking that would solve your problem. Run a high loop, (see image) and replace the old air gap with a soap pump, a chrome cock hole cover or a hot water dispenser. Good luck, Tom PS. In all the hundreds of high loops my company has installed plus the countless counter top air gaps that we have advised on this site we have NEVER got the first complaint from anyone.