Your local plumbing code may require an airgap to pass inspection, but there's no requirement that says it has to be used. Quite a few posters here have had the airgap installed, then either ignored it or removed it after their final inspection and put a soap dispenser or some other accessory in its place.

Miele dishwashers have a built-in anti-siphon device so an airgap isn't needed. In fact, Miele specifically recommends against connecting the drain line to an airgap which can constrict the flow of draining water. So, even though you have an airgap in place to satisfy local code, you can simply ignore it and safely connect the Miele drain line directly to the dishwasher drain nipple on the side of your garbage disposer or to the dishwasher drain nipple on your sink drain line. The built-in anti siphon device on the dishwasher will prevent any possibility of water from the house drain lines being siphoned into the dishwasher.

There is no state-wide code in California requiring an airgap, but your city or county may have such a requirement.

We have done projects in Santa Barbara and San Fran in which no airgaps were used with Miele DWs.

Different locales have different codes, even in the same county. If they are a friend, you're not going to turn them in even if they did violate the code, right? So what does it matter? All that matters is what YOUR local inspctor thinks! If your local codes require it, there is no fighting the inspector to get around it. YOu'll just create trouble for yourself. Put it in, and perhaps use the hole for a soap dispenser at a later time after the inspection.

Hi pedimom,

You still need a high loop, if the P trap is in the kitchen and not in the basement.

All dishwashers work well without an air gap.
This fact doesn't contradict the above posts.

As you wrote it in your first post. it can be misleading to say that Miele's don't "need an airgap because of the way they are built" --

I emailed Miele this morning about this topic. After three follow-up questions by email, I think I can say with certainty that Miele is not against connecting the drain line to an airgap. However I don't want to be the sole person defending Miele or their Customer Support people. Misunderstandings can happen too.

Note that it may be false to say "... Miele specifically recommends against connecting the drain line to an airgap which can constrict the flow of draining water..."

Many dishwashers have anti backflow devices.

In the G2430SC manual I found this: "...Otherwise the water inside the dishwasher may siphon out during the wash program... " This makes me think their anti-backflow is a one-way device preventing water from flowing back into the DW (this can be "siphoning", in plumbing terms).

Another use of the term "siphoning" is to describe water being siphoned out of the DW, not into it. This can happen when you route the drain hose straight through the floor. More about this if necessary, later.

Read your Use and Care guide. Call Miele. Report your findings her on this thread for more sharing.

See http://ths.gardenweb.com/forums/load/appl/msg121347519992.html

David

Here is a link that might be useful: clear description of air gaps and high loops

I'm glad you agree with me anntss. High loops are great!

Good to know there is a 30 second mod, too.

I'm glad you agree with me anntss. No DW needs an air gap.

Anything else?

Dallas, TX, code requires an air gap. We were able to have our Miele dishwashers (2 Excellas) installed last year without the air gap by showing the city inspector documentation from Miele that certifies that Miele has built in air gap protection, satisfying the code. This is not in the Miele manual; I requested additional documentation from Miele in advance, after reading about it on this forum.

We also appreciate the leak detection feature.

David seems to have this "high loop" requirement theory of his on the brain. He's not going to give up on it until he convinces someone that he's right. He's not...but it makes no difference. He'll keep flogging the notion as long as anyone will pay attention.

While a high loop probably doesn't affect the dishwasher's operation, it's totally superfluous on a Miele dishwasher.

On a dishwasher without a built-in anti-siphon device (and there are many), a high loop offers some protection against siphoning, but it's not a fool-proof substitute for an airgap. That being said, situations that can lead to siphoning are not common. Most dishwasher owners will never experience it, with or without some type of anti-siphoning device.

Yes David - Miele does not NEED a high loop.

wa8's last paragraph about sums it up, a high loop and/or airgap has it's place, but is not the be all - end all of DW plumbing. The code and these devices/techniques are meant for most installs in most situatiuons but are not the authority in every case.

Whether the dishwasher needs it or not, in SF the airgap is required by code. Despite our dishwasher specifically not requiring one, we didn't pass our inspection because of the lack of an airgap. Luckily we had a soap dispenser which we removed so we could use that (already drilled through the soapstone countertop) opening for the airgap. Once the inspection was signed off, the airgap came out and the dispenser went back in!

Part of the documentation we received from Miele was a City of Los Angeles document approving Miele dishwashers without an airgap. LA still requires all other DWs to be installed with an airgap.

thank you all for the advice. I guess i should go to my City department to see if the miele's are required to have an airgap. My contractor has done several homes in SF and the Peninsula where i live so I'm sure he's familiar with the codes, however, i don't think he has installed a Miele. I will also contact Miele to get verification from them.

Do we need an airgap for the fisher and paykel dishdrawers?

There is no DW that needs an air gap. It is not a DW requirement.

I repeat that For All makes or models of DW there is no need for an air gap.

It is totally false to claim anything about one brand or make in relation to air gaps. E.g. that one brand is so good because it alone doesn't need an air gap. (I have seen this written all over GW for ages so I am posting it here now to be real clear.

-david

So David, what's your point? I don't believe anyone has ever claimed that any dishwasher requires an air gap. All dishwashers will function just fine without one.

The point was, that there are some local or municipal plumbing codes that require an air gap if there is a place in the kitchen for a dishwasher installation. The plumbing code requirement has nothing whatever to do with any mechanical requirement of a particular brand or model of dishwasher.

There is not, however, any prohibition against bypassing the air gap. You simply need to have an air gap in place to pass the plumbing inspection, which in most cases is done before any appliances are installed anyway.

After the final inspection, if you're installing a dishwasher with a built-in anti-siphon device, you can rest assured that bypassing the air gap poses no increased risk that water from your house drain lines could be siphoned into the dishwasher.

On the other hand, if in the absence of a built-in anti-siphon device you want the same protection, you'll need an air gap. A high loop does not afford the same level of assurance against siphoning. Plunging a clogged drain with a dishwasher drain line attached, could result in water being forced into the dishwasher. Only an air gap or a built-in anti-siphon device would prevent that. A high loop won't do it.

In and of itself, back-flow into the dishwasher from your house drain lines isn't the end of the world, and certainly poses no threat to public health and safety. It could be a bit yucky, though. No one relishes the thought of contaminated drain water coming into contact with their dishwasher interior. Beyond that, if enough water were forced into the dishwasher by plunging, it could result in an overflow, potentially leading to some flood damage.

I was discussing this with a friend of mine, who has a general contracting license. I thought he looked it up (I live in Ca.) and said it WAS in the code.

I could be wrong, and if I see him soon, I'll get the code, or apologize.

How do I know if the fisher and paykel drawers have the anti-siphon device. I was told that they did and that i could just put the airgap in to pass inspection and then take it out. My plumber said there was an additional part needed from F&P and I am trying to figure out what that is.

I went to the F&P showroom in a big city. The showroom run by the Distributor.

There, they supposedly know everything. They all assumed I would run a high loop. (Almost equivalent to an air gap, but under the counter top.)

It is good to plan for a high loop. All DW pumps are designed to push water H2O up a little distance in the hose. This is normal.

-david

California Plumbing Code is pretty clear about this subject:

414.3 Drainage Connection. Domestic dish washing machines shall discharge indirectly through an air-gap fitting in accordance with Section 807.4 into a waste receptor, a wye branch fitting on the tailpiece of a kitchen sink or dishwasher connection of a food waste grinder

Wasn't it stated earlier in this thread that there is no *STATEWIDE* requirement for air gaps in California? The code for this is set at county or city levels.

I'm in California and when I asked bout this several years ago, the local city inspector said he would sign off on Miele dishwashers without an air gap with proper documentation from the manufacturer.

Where does Miele document this if it isn't printed in the owners manuals?

Also, is a building inspection even required for a simple swap of an existing dishwasher? If not, there is no reason for a building inspector to even be involved. An air gap can be installed just before the house is put on the market if you plan to sell and don't want to deal with getting special approvals/waivers during the new buyers home inspection.

I don't even mind having an air gap on the counter cosmetically. The issue I have is the very loud and distracting noise of water and air gurgling/echoing during every drain cycle. This 100% defeats the purpose of paying extra to get a super quiet dishwasher.

If air gaps didn't create so much added noise, I wouldn't worry about them.

"Wasn't it stated earlier in this thread that there is no *STATEWIDE* requirement for air gaps in California?" - They can state it all they want, but it does not make it true.

"The code for this is set at county or city levels." - No, just whether the local inspector actually performs their job accurately. Legal local amendments are only allowed for seismic, geographic, and local weather conditions, and must be approved by the state. A dishwasher inside the house would not be affected by these conditions.

Here is the CPC, otherwise known as the statewide plumbing code.

[https://www.houzz.com/discussions/air-gap-in-california-dsvw-vd~2621334[(https://www.houzz.com/discussions/air-gap-in-california-dsvw-vd~2621334)

[https://www.houzz.com/discussions/air-gaps-and-california-code-dsvw-vd~2406462[(https://www.houzz.com/discussions/air-gaps-and-california-code-dsvw-vd~2406462)

[https://www.houzz.com/discussions/air-gaps-and-california-code-dsvw-vd~2406462[(https://www.houzz.com/discussions/air-gaps-and-california-code-dsvw-vd~2406462)

The other issue is how much of the noise is coming from the air gap and how much of the noise is coming through the drain hole in the sink.

Many of the other people who are trying to avoid air gaps want this because they don't like the looks of them, but my primary reason is because I don't want to hear the drain noise from the dishwasher.

If the water can drain quietly even with an air gap installed, then I don't mind having it. The hole is already cut in the granite for the air gap and I don't need a soap dispenser because there is already one on the other side of the sink.

Just because they keep claiming it does not make it true. State law specifically prohibits such local amendments. The people on these forums just do not get that, and so they try to explain it away as a code change... because they would hate to believe that the inspectors are really that lax on all the structural issues the builder has them overlook as well. It is not, and can not be a legally documented amendment. Only the legislative branch of the govt can do that. It is however, the reason the words "above the flood level of the sink" were added since these posts.

What the inspector will look the other way on has nothing to do with what the actual legally written and adopted code says. An inspector is not even part of the Legislative branch of the govt. You will not find any helpful information here, other than the frequent suggestion to grovel at the feet of the inspector. They are easily bought...or fooled.

My experience is that having the air gap slightly reduces the chance that a drain backup will backflow into the dishwasher. It is possible for the check valve in the dishwasher to get a small piece of food (a carrot strip in my case) between the ball and the seat, which will then allow backflow.

And it's not difficult. The Miele hose is 7/8", designed to connect directly to the garbage disposal. The barbed connecter on the air gap is 5/8". Cut a short length (about and inch and a half) of 5/8" rubber hose and push it onto the air gap connector, then push the 7/8" hose over the 5/8" hose and tighten the clamp. Works quite well; the 5/8" hose is almost the perfect O.D. to act as a reducer bushing.

My airgap has an extra "input" to allow for the use of an RO drain, so it is designed for relatively high flow. Haven't observed any issues.

If you need to extend the factory Miele hose (I did) use a short length of 7/8" rubber hose (better flow than extending with a length of 5/8" hose). If you can find a 7/8" barbed hose connector (to connect the factory drain hose to the rubber extension hose) use that. (I had difficulty finding one). So I used a 3/4" PVC sprinkler riser, which has an O.D. of about 1" (it's what I had). I threaded the 7/8" rubber extender hose onto the riser, using a small amount of sealant, and it's a nice, secure fit. The factory Miele hose is relatively soft rubber and stretched to fit the other end.

Sounds a bit hokey I know. But the proper connectors and reducers that you would want to use seem to be next to impossible to find.

Hope this helps. Great dishwasher BTW, love it.