Are air gaps necessary on a dishwasher? How do you avoid it?
brianadarnell
13 years ago
Featured Answer
Sort by:Oldest
Comments (24)
randy427
13 years agobrianadarnell
13 years agoRelated Discussions
Help installing KitchenAid dishwasher without air gap
Comments (4)If you can send the drain down through the floor to a lower level P trap, you can do that. My saying this is not a recommendation "per se" in and of itself, it is just information, which may need further caveats. If the P trap for this DW is in the kitchen, you need to install a high loop. If you know what a high loop is, install that. High loop means to raise a portion of the dishwasher's flexible drain line as high as you can under the sink (e.g. with a piece of bailing wire). This will prevent contaminated water from backing into your dishwasher, unless the backup goes right up to the rim of your sink, in which case, an above-sink air-gap is the only thing that will prevent cross-contamination. The DW drain line branches into the sink drain line below the sink -- regardless of what type your faucet is. I suspect you have a contractor who I would consider a case of borderline fraud. Your contractor must know what a high loop is. He also must know that any dishwasher drain connecting to the kitchen P trap goes first through a high loop or an air gap. In both cases (high loop and air gap), the drain plumbing connection has no relationship to the faucet you chose to install. That is supply plumbing not waste plumbing. Perhaps I have misunderstood your post or you have misunderstood what you thought he said, or some other explanation is possible, et cetera. If not, you have a special case of a contractor saying that the faucet prevented him from raising the dishwasher hose in a high loop and thereby routing its waste water up first before it goes down into the P-trap and the house drain. HTH David...See MoreObnoxious Air Gap Noise From Draining Dishwasher
Comments (34)You are right. Sorry I didn't catch that, in the image. You cannot leave it that way. You already know most of the big reasons why not. If you need to read all the problems, find out about sewer gases. Some are lethal (but my saying this is not designed to give you nightmares). The DW connection has to go on the other side of the P trap. You can buy more hose instead of replacing that one. Radiator hose for car motors is good because it is smoother inside. The reason these cheap hoses are corrugated is to ensure they never collapse. A smoother inside wall can reduce noise quite a bit - not in all cases, as it depends on the flow and how you configure the geometry of the fall. HTH -david...See MoreAir gap gurgles like crazy when dishwasher runs - should it?
Comments (17)zl700l, I don't believe there would be anything in a dishwasher that would be sufficient to act as an effective p-trap and I do believe you are basically bathing the dishes in your dishwasher in sewer gas, not to mention airbourne bacteria. The explosion risk of the methane entering the dishwasher is not to be ignored either, I am sure there is plenty of potential ignition sources in there to be of concern, moreover, people die in homes infiltrated by sewer gas. The risk is not to be scoffed at. Moreover, it's just common sense- the practice is dangerous and illegal, makes your house unmarketable and subject to being condemned or remediation orders, and just a bad idea. We're talking about a little gurgling water, not freeway noises. I like hearing the dishwasher when it drains because a) I know it's working and how far along it is, and b) having it drain into the p-trap means that it's charging it (keeping it full, avoiding gas infiltrations) and the dishwasher detergent going through the trap keeps it clean and smelling decent. As the the 'banjo' vs 'my house is bigger than yours' contest, I don't believe in being rude as it were but I believe it's not a question of how much money someone has, but how much common sense /stubbornness they have....See MoreBosch Dishwashers don't need air gaps?
Comments (13)I installed an air gap for my dishwasher because it made sense to have it for sanitation safety purposes. If your Bosch dishwasher has a backflow preventer then you're that much safer, but why not have both in case the backflow preventer on your dishwasher fails. However, if you want to check the code then you could call the San Francisco Office of Building Inspection and ask them. I also did a quick online search and this is what I found. From the 2013 California Plumbing Codes (Scroll down to page 56): "414.3 Drainage Connection. Domestic dishwashing 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. Commercial dishwash- ing machines shall discharge indirectly through an air gap or direct connection in accordance with Section 704.3 with floor drain protection." http://www.iapmo.org/2013%20california%20plumbing%20code/chapter%2004.pdf From the City of Palo Alto, Building Division, Final Inspection Form (scroll down to the top of page 16): "Airgaps required - No domestic dishwashing machine shall be directly connected to a drainage system of food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood-level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher.(2010 CPC section 807.4)" https://www.cityofpaloalto.org/civicax/filebank/documents/17668 Palo Alto is close to San Francisco so I imagine they would follow similar plumbing codes....See Morebreezygirl
13 years agobrianadarnell
13 years agobreezygirl
13 years agovpierce
13 years agobrianadarnell
13 years agodavidro1
13 years agoartemis78
13 years agomarcolo
13 years agoathomesewing
13 years agoigloochic
13 years agodavidro1
13 years agosandsonik
13 years agobrianadarnell
13 years agoalku05
13 years agobreezygirl
13 years agoDavid Bradford
8 years agoHU-627855707
3 years agoHU-627855707
3 years agoJoseph Corlett, LLC
3 years agoHU-77931829224
2 years agoJustin Kemp
last year
Related Stories
PETS5 Finishes Pets and Kids Can’t Destroy — and 5 to Avoid
Save your sanity and your decorating budget by choosing materials and surfaces that can stand up to abuse
Full StoryHOUSEKEEPINGTackle Big Messes Better With a Sparkling-Clean Dishwasher
You might think it’s self-cleaning, but your dishwasher needs regular upkeep to keep it working hard for you
Full StoryHOUSEKEEPINGDishwasher vs. Hand-Washing Debate Finally Solved — Sort Of
Readers in 8 countries weigh in on whether an appliance saves time, water and sanity or if washing by hand is the only saving grace
Full StoryMOST POPULAR5 Ways to Hide That Big Air Conditioner in Your Yard
Don’t sweat that boxy A/C unit. Here’s how to place it out of sight and out of mind
Full StoryKITCHEN DESIGNHow to Choose the Right Hood Fan for Your Kitchen
Keep your kitchen clean and your home's air fresh by understanding all the options for ventilating via a hood fan
Full StoryGREAT HOME PROJECTSWhat to Know Before Refinishing Your Floors
Learn costs and other important details about renewing a hardwood floor — and the one mistake you should avoid
Full StoryMOST POPULARA First-Time Buyer’s Guide to Home Maintenance
Take care of these tasks to avoid major home hassles, inefficiencies or unsightliness down the road
Full StoryKITCHEN DESIGN9 Questions to Ask When Planning a Kitchen Pantry
Avoid blunders and get the storage space and layout you need by asking these questions before you begin
Full StoryREMODELING GUIDESConsidering a Fixer-Upper? 15 Questions to Ask First
Learn about the hidden costs and treasures of older homes to avoid budget surprises and accidentally tossing valuable features
Full StoryHOUSEKEEPINGProtect Your House From Winter Water Damage
Avoid costly repairs by learning to spot potential problem areas before water damage is done
Full StorySponsored
sherriz