Loop for Dishwasher Drain Pipe

We had a new dishwasher put on last summer. No problems until this summer when we had new countertops and new undermount sink etc. We used this opportunity to purchase a new Sinkerator Premium 3/4 hp disposal or whatever the model was called.

A day or two after they finished, I noticed that the dishwasher had water in it. So I looked up the problem in the internet and this site and learned about the loop etc. We don't have an air gap. I've attached a pic. Will simply looping the pipe up solve the water backing up issue? Thx in advance for your thoughts.

You need to run the hose up to under the couter as high as you can go. The way it is, any clog will put crud from the sink into the DW, a very unhealthy situation. Depending on where you live, you may be required to install an air-gap. If you had one, that situation would be essentially impossible.

You have enough slack on that line for a raised loop. Attach it to the underside of the counter with a clamp. That'll solve your problem.




...Is it me, or are a lot of this weekend's questions about fixing work done by hacks?

Did you knock out the dishwahser plug?

The sad thing is that the granite counters and cabinets were done by a very reputable company. They do the faucet and disposal hookups and part of the service (and would've addressed had I said something) but clearly this why a licensed plumber always get hired when we need work done in the house.

frenchie said:

...Is it me, or are a lot of this weekend's questions about fixing work done by hacks?

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Oh yeah, our code doesn't require air gaps. Never had this problem before this, but I presume the loop will be an easy & quick solution.

Depending on where you live, you may be required to install an air-gap.

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??? I will have to look up what that is.

palmstate said:

Did you knock out the dishwahser plug?

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Where the dishwasher hose connects to the disposal. There is a plastic plug in there incase you don't have a dishwasher attatched.

I don't think so. If I plug the sink, then fill it with soapy water, you see some of the water go thru the disposal and into dishwasher hose so there's nothing plugging the water from the disposal ... if that makes any sense.

palmstate said:

Where the dishwasher hose connects to the disposal. There is a plastic plug in there incase you don't have a dishwasher attatched.

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lpennington said:

We had a new dishwasher

A day or two after they finished, I noticed that the dishwasher had water in it. So I looked up the problem in the internet and this site and learned about the loop etc. We don't have an air gap. I've attached a pic. Will simply looping the pipe up solve the water backing up issue? Thx in advance for your thoughts.

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It's a cross-connection between a device for sterile utensils and your bacteria-laden waste pipe.

High looping is still a direct connection to the waste system, once momentum starts to roll, it's the same as a garden hose siphoning water over top the edge of a pool.

Oh yeah, our code doesn't require air gaps. Never had this problem before this, but I presume the loop will be an easy & quick solution.

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Quick and easy?

The licensed plumbing contractor for lowes in my area is going to feel my wrath come monday afternoon when his nonsense of not installing the new dishwasher to code, which involves an Air Gap. He blatantly lied to the customer stating they didn't need it because there is a check valve thingy that is built into the dishwasher. An Air Gap offers the best level of protection in all backflow situations and has no moving parts to wear out and fail. It uses the free atmosphere to protect.

That check valve thingy is is a mechanical device that can and will fail. The dishwasher was installed in Kentucky so my two trips totalling $85/hour to correct their ignorance is going to make sure they install plumbing to code.

Telling them doesn't work; hitting their back pocket along with an irate customer who won't hesitate to turn them into the BBB or AL has a good way of fixing stupidity.

That installation above looks like a shoddy install. That doesn't even look like a continous waste tee; end outlet tees don't have a bottom nut......the pipe connecting to it will though. It looks like a center outlet tee turns sideways with the baffle cut out. ALSO, that gray PEX line heading to the dishwasher; better replace that soon because those are notorious for leaking at the connections due to the vibration of the dishwasher. GOOD LUCK

No wander you're on here with plumbing problems!!!!

Palm, how would he be getting water in the dishwasher if the plug wasn't out?

Pennington - ignore Palm, he obviously didn't read your post.

In jurisdictions where an air gap isn't require, a high loop is still needed - it's in the dishwasher installation instructions, and the hanging bracket for the hose usually come with the DW. Just raise a section of hose between the two, you'll be fine.



Edit: Rugged - really? All the DWs I've ever seen put in, here, just had a high loop. Never a problem. Did my plumber set up a bunch of illness traps? You're scaring me...

frenchie said:

Edit: Rugged - really? All the DWs I've ever seen put in, here, just had a high loop. Never a problem. Did my plumber set up a bunch of illness traps? You're scaring me...

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I tell you this logic straight from being a master plumber and a licensed backflow tester in my state: YES

Whether that code is laxed from state to state, whether your brother from minnesota or your aunt claude from michigan has had a dishwasher with no air gap for 40 years,

that drain line is directly connected to the dishwasher.

Why else was this thread started.....along with the 1000's I see across many plumbing forum boards. It's a direct connection and the high-looping only increases the odds of it not happening, not preventing.


Here's one for the non-believers:

When you have a clogged kitchen sink and you start to plunger those drains, where does the waste water go?

Dishwasher.

I'm vocal on this subject matter because there are those who will never reply to this thread that understand the logic behind the necessity to protect.

Did you know that every commercial dishtank machine at a restaurant that creates sterile eating utensils must have an Air Gap is code in all 50 states and maybe mexico?

Why it relaxes on the residential side of plumbing I'll never know, but I've convinced people in non-code areas of the seriousness of the issue, most people that have families are the first to commit when I spell out the dangers. Others like to take chances.

RUGGED said:

No wander you're on here with plumbing problems!!!!

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Not sure WTF that meant ... I didn't do this myself (I just observe and ask). I do appreciate your insight and even your tone as now I've been spurred to just have our normal plumbing company take care of this.

I just went through this new dishwasher, new sink, new countertop exercise, and all the pro parties involved and the county plumbing inspector said all they require is a high loop, so that's what I've got.

Having said that, Rugged has made a believer out of me. My questions (finally) are: how big a hole do I need in the countertop, is there any requirement to position it in any particular place, and what kind of horizontal clearances do I need below to install one of these things? It's pretty tight under there.

A few minutes with my buddy Google and I've answered those questions. I also found air gap units priced from $3.99 to $35. Any recommendations? What makes the $35 one more "deluxe"?

I ended up looping the dishwasher hose from directly where it exits the disposal into an upside-down "U" for approx 10 inches and then it goes down into the dishwasher.

I filled the sink with soapy water and then drained it with the disposal on and no water made it up and around the "U". I'll let you know what our plumbers say (a Lowes installer coincidentally installed this dishwasher!).

lpennington said:

I ended up looping the dishwasher hose from directly where it exits the disposal into an upside-down "U" for approx 10 inches and then it goes down into the dishwasher.

I filled the sink with soapy water and then drained it with the disposal on and no water made it up and around the "U". I'll let you know what our plumbers say (a Lowes installer coincidentally installed this dishwasher!).

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Point worth mention, and I won't deny personal agenda....in my area:
The "Box" stores sub out the work to guys like me at a fraction what I'd get on my own...It's an incentive to attempt to get markups by adding on more work like "Sir, you're drain isn't going to hold for long...I'll have to replace it", "These water pipes are on the way out..."
When you're making a third what you normally make to install a water heater...well...ya gotta hustle, make up for it in less time.
I can't put down my fellow tradesmen who work hard, but I don't think it's right that they send a fella in with his own vehicle and tools, deny him employment benefits as a "contractor" and still yet cut his earnings by underbidding what locals can do it for and still take a cut for themselves, because they have marketing/buying power.
I inquired about subbing from them, when I found out what my rates would be I immediately said no, I knew it would be trouble.
Someone, somewhere is going to cut one too many corners in order to make a living, and it won't be good.

lpennington said:

Not sure WTF that meant ... I didn't do this myself (I just observe and ask). I do appreciate your insight and even your tone as now I've been spurred to just have our normal plumbing company take care of this.

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I understand you didn't do the work, but I do understand why you had to post this problem after seeing the lazy install. What would of happened if you got sick using those dishes that came out of the dishwasher, unaware there was waste water in the bottom? Trust me, if you do like most do, pick a few forks here, a couple cups or saucers there, you won't see the bottom until you get all the dishes removed. That waste water makes people sick, no way around it.

Nothing irks me more than seeing good people paying good money and find out after the fact that the work was done incorrectly. The sink I'm going to be under tomorrow had the dishwasher hooked the same way.

(a Lowes installer coincidentally installed this dishwasher!).

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I'll keep you posted on the outcome of my "branding" of the installer of my customer's dishwasher.

Mikey,

They all do the same thing, they all have the same configuration. It's just a better mousetrap when it comes to the pricing. High end finishes, or a copper/brass assembly against plastic.

The $4 home depot ones are no good; the threads are too shallow and the nut releases with any amount of strain. A Moen or Delta Air Gap will work good, Moen has a trim ring that will allow you to never see the plastic ring at the bottom.

With an open mind I try to see outside my code book and understand why there are enforcements of certain codes that are not enforced in my state.

Take away my tinning flux and make me use purple primer, we got problems.

RUGGED said:

Take away my tinning flux and make me use purple primer, we got problems.

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HA!
We don't use that purple crap either!
I get it all the time from guys in UPC states that don't seem to understand how drainage doesn't leak without it...in fact the only place that sells it is HD or lowes...so it's associated with DIY work when inspectors are coming.
I cringe at the thought of knocking over a can of it under a finish KS with hardwood flooring or light tile.
OH...for what it's worth...I'll try yer tinning flux...it better be good!

Palm, how would he be getting water in the dishwasher if the plug wasn't out?

Pennington - ignore Palm, he obviously didn't read your post.

If the plug wasn't removed and the diswasher drained where would the water go except for back into the dw? I've seen it happen before. The problem did not happen until a new garbage disposal was also installed so it is a logical theory to what the problem is as well as there being no high loop.

palmstate said:

Palm, how would he be getting water in the dishwasher if the plug wasn't out?

Pennington - ignore Palm, he obviously didn't read your post.

If the plug wasn't removed and the diswasher drained where would the water go except for back into the dw? I've seen it happen before. The problem did not happen until a new garbage disposal was also installed so it is a logical theory to what the problem is as well as there being no high loop.

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Ya know...he has a point there...I stand guilty as charged of said oversight, yup...had to drive back once or twice to poke the stupid thing out.