dishwasher/sink flood

randekaspNovember 16, 2010

I posted this in plumbing as well, hope that is OK. Until I am clear about how "loop" is, I am wondering if it is safe to use the diswasher itself. Here is the post and brief followup:

New dishwasher installed last year without airgap. Think/hope contractor used the "loop" system discussed elsewhere on this forum.

Suddenly, WITHOUT dishwasher running, water from sink went to bottom of dishwasher, did not drain, but ran out bottom of dishwasher onto floor. Sears came out (does anyone else now believe that Sears is beyond terrible?) Technician said nothing wrong, guaranteed that an undercounter airgap will resolve issue. I read here never to do that. So.... Any ideas appreciated. Thank you.

"high loops" are often configured improperly. My new DW with "professional" install was botched this way. Knowing what to look for, I fixed it myself. Very easy. The peak of the loop must be secured above the level of the sink-lip....right up there under the counter. However, even then, if your sink is really full the surge from opening the drain can push water over the high loop. Once that occurs, the siphoning can continue until the sink's empty. I suspect that's what happened. An air-gap installation will prevent this. That's why many people have suggested that ALL codes, not just some, should require air-gap installs.

Your dishwasher will not drain unless the drain pump is operating. Once the siphoning action began, you were doomed unless you recognized it and stopped the drain immediately.

"The peak of the loop must be secured above the level of the sink-lip....right up there under the counter."

Securing it to the bottom of the counter (and making sure it stays there) is all that is required.

While it could still cause a backup if the sink is filled to overflowing, kitchen sinks are not normally filled that high.

The important thing is to get the loop high enough that normal use of the sink never allows water higher than the loop.

Thank you for reporting this comment. Undo

You can run the dishwasher. Your problem was a surge from the sink beginning siphoning down to the dishwasher. If there's nothing to cause that siphoning to begin, you'll be fine. In other words, just keep the sink empty until you have clarity.

    Bookmark   November 16, 2010 at 12:49PM
Thank you for reporting this comment. Undo

Thank you!

    Bookmark   November 16, 2010 at 1:22PM
Thank you for reporting this comment. Undo

If your plumbing can accommodate it, you can also use a separate stand pipe with the dishwasher output hooked into it just as most clotheswashers are hooked up. This way you get an effective under-counter air gap, the dishwasher does not connect to the garbage disposal, and potentially the noise is reduced.

The IPC has a specification for the minimum height between the top of the standpipe and the weir of the standpipe trap, but I don't recall exactly what it is.


    Bookmark   November 16, 2010 at 10:02PM
Sign Up to comment
More Discussions
Noxious new oven smell ??
Our new Electrolux wave-touch double oven is wonderful,...
Help installing power cord to 48inch dual wolf range
I'm trying to install the power cord, not sure how...
How much Hood CFM to get for Wolf's 6-Burner Rangetop?
Let's say I use all 6 burners at once sometimes (not...
Buy 2 individual wall ovens or one 2 oven wall unit?
Hi - I'm looking for appliances for a house we will...
Any thoughts about Bosch and GE Profile appliances?
I am building a passive house and trying to choose...
Sponsored Products
Vietri Set of Four Lastra Fish Mugs
$149.50 | FRONTGATE
KOHLER Bathroom Kathryn Pedestal Combo Bathroom Sink in Almond brown K-2322-1-47
Home Depot
Ruvati RVM4310 Undermount Stainlesss Steel 32 Kitchen Sink Double Bowl
$249.00 | Blue Bath
Waechtersbach Uno Soup/Cereal Bowls Curry - Set of 4 - 44S4CL0030
$32.00 | Hayneedle
Virtu USA Bathroom Caroline Parkway 36 in. Single Vanity in Espresso with
Home Depot
Polaris 18 Ga: Sink Standard Strainer
Modern White Unique Bathroom Sink By MaestroBath
Cuisinart GR-4N Griddler - GR-4N
$99.95 | Hayneedle
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™