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Hooking up dishwasher drain question

Posted by jk55 (My Page) on
Tue, Apr 3, 12 at 16:40

I just had a remodel done to my kitchen. I had a peninsula built and moved the dishwasher from next to the sink over to the peninsula. The plumber (30 years experience) hooked up my dishwasher by drilling a hole through the tile down into the cellar and connected the drain hose to a 2" drain pipe which was formerly used for my washing machine before we built a laundry room on main floor 20 years ago.Hence, this pipe has not been used for 20 years. This 2" pipe connects to the main drain for the kitchen. In the meantime, right after the plumber left, the stove installer come to install my new stove. He went down into the basement to check the circuit box for the stove installation, and noticed the new plumbing for the dishwasher and proceeded to tell me that it was done incorrectly, not to code, and that I may burn out my dishwasher motor and have water siphoning up back into the dishwasher. He said that the drain hose must be hooked up 20 inches above the kitche floor to eliminate this. The plumber did not do this because did not want to drill through my new cabinets, and also said that the hose would lay inside the cabinets and may get disturbed and promote leaking. This is why he went through the floor. He said this was the easiest and most sensible what to do this since the old washer drain was already there in place and connected to the main drain/ Again, he is very experienced, I called him to tell him what the stove installer said and he said basically he was wrong and that it was done correctly and that he does jobs like this in kitchen islands all the time. He said something about there being a "trap" in the pipe downstairs. I don't know what this really meant.
So, who is correct????


Follow-Up Postings:

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RE: Hooking up dishwasher drain question

There are some detailed drawings on how to connect a dishwasher drain on this site. You may want to do a search.

That said, my guess is that you aren't really in a position to challenge your plumber on your own- and without pictures, we can't really say for sure either.

What I would suggest is that you first talk to your plumber and diplomatically suggest that it wasn't done correctly without going into too much detail. Give him the opportunity to correct it before you call someone else in and bill him back for the repairs. Ask him if he would be okay with a building inspector looking at what he's done.

The other approach is to conclude that the work that was done is grossly wrong - which I suspect is case, but I can't confirm without pictures -- and that the original plumber shouldn't step foot in your home again.


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RE: Hooking up dishwasher drain question

On the other hand,,perhaps the stove installer proved why he is delivering appliances instead of working in the plumbing industry


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RE: Hooking up dishwasher drain question

I'm with you Lazypup, If I were the plumber I wouldn't want a delivery guy (or folks on the internet) second guessing my work. From the description though, it doesn't sound legit.


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RE: Hooking up dishwasher drain question

"Give him the opportunity to correct it before you call someone else in and bill him back for the repairs. Ask him if he would be okay with a building inspector looking at what he's done."

Regret to say I agree with this. "Code" is important...for yourself and absolutely if/when you may choose to sell the property. You should have confidence all is correct....from the beginning. Understand you are not personally qualified to judge so bad place to form an opinion. Someone else will have to be brought in.


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RE: Hooking up dishwasher drain question

"From the description though, it doesn't sound legit."

The stand pipe is an indirect waste.

You may be fine.

There is no way a flood in the standpipe would be able to drive water back up the drain hose as long as he did not do more than terminate the hose in the pipe (not glued, not enclosed, just stuck into the pipe).


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RE: Hooking up dishwasher drain question

without reading too closely, JK, you need to make sure the drain hose is looped up high in the cabinet, if it is not already done by the DW itself. Else it could drain out on its own before the wash cycle is complete.


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RE: Hooking up dishwasher drain question

"you need to make sure the drain hose is looped up high in the cabinet, "

Why?

He has an indirect waste (what an air gap creates) and unless the line is sealed to the standpipe, nothing can flow back up.


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RE: Hooking up dishwasher drain question

Perhaps its because the codes require both the high loop and connection to an indirect waste. And regardless of whether there is a high loop inside the machine, code still requires the drain line to be configured with a high loop.


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RE: Hooking up dishwasher drain question

"code still requires the drain line to be configured with a high loop."

What code requires both?

All I remember seeing are one or the other, not both.


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RE: Hooking up dishwasher drain question

Instead of trying to argue the point with my, why don't you look it up in your own code?

Here it is from the State of Virginia Plumbing Code;

802.1.6 DOMESTIC DISHWASHING MACHINES
Domestic Dishwashing machines shall discharge into an airgap or air break in a standpipe or waste receptor in accordance with section 802.2, or discharge into a wye branch fitting on the tailpiece of the sink or into the dishwasher inlet connection of a food waste grinder. The waste line of a domestic dishwashing machine discharging into a sink tailpiece or food waste grinder shall connect to a deck mounted air gap or the line shall rise and be securely fastened to teh underside of the sink rim or counter.

Now for your enlightenment, a wye branch on the tailpiece or a dishwasher inlet port on a food waste grinder are both indirect waste connections.


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RE: Hooking up dishwasher drain question

And the high loop is only required if the air gap is not present AND you are using a sink tailpiece.

Maybe yo did not read carefully?

A stand pipe with an air break does NOT need the high loop.


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RE: Hooking up dishwasher drain question

On the other hand,,if you were to really read the code you would know that the opening on a standpipe must be a minimum of 18" above the water level of the trap, and the connection at the top of a standpipe is both an air gap and a high loop


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RE: Hooking up dishwasher drain question

hi jk, ya gotta know what a trap is, first. Using any web search engine, go learn that it's a good thing in plumbing.

"P trap"

If the dishwasher hose goes through the floor into the basement, it might be an OK install, according to some manufacturers. Those manufacturers don't call for a high loop there. It is for situations where the P trap is above the kitchen floor.


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