I am installing a new dishwasher in new cabinets. I am not installing an air gap and I planned to put a high loop under the countertop. However upon unpackaging the dishwasher I see that it has a built-in high loop in the drain line (attached to the side of the dishwasher itself). Since the high loop is already there, I could just make the hole through the cabinet near the top. If I the hole at the bottom, I would not be able to make another loop as the drain line would be too long. If I don't need another loop, then I could put the hole anywhere. I think I don't want to loops anyway. Has anyone solved this situation? I could remove the loop on the side of the dishwasher and make my own under the sink.

Since the high loop is already there, I could just make the hole through the cabinet near the top.
Hold the phone! If you have a high loop why in the world are you drilling a hole in the counter top?
I can't believe a dishwasher comes with a higfh loop the reaces to the underside of the counter top, (see images).

I could remove the loop on the side of the dishwasher and make my own under the sink And that's what I would do. Good luck, Tom

Yes, indeed, some dishwashers, like Bosh, Viking, Fisher Paykel, have high loop incorporated into their design. You can either utilize their set up and just connect the loose end of drain into the sink drain. Or, you can unhook the manufacturer's high loop and create your own. You should be fine both ways...

Thanks Milo, The bult in high loops came along after I retired. Thanks for the update. Tom

Hold the phone!! If you have a high loop why in the world are you drilling a hole in the counter top?
I can't believe a dishwasher comes with a higfh loop the reaces to the underside of the counter top, (see images).
And that's what I would do. Good luck, Tom

Thanks for the reply. No, if I left the loop on the side of the DW, I wasn't going to drill a hole in the countertop. If I left that loop in place, I was thinking of making the hole in the cabinet, as high as I could, near the top. Then I wouldn't need another loop under the sink.
But you're right, the loop on the DW goes almost to the top of the DW, but is probably at least an inch below the underside of the countertop. So, I can think of 3 reasons to remove the loop from the side of the DW and make my own under the sink - 1) the high loop on the DW is at least an inch lower than a high loop I can make under the sink, 2) a high loop under the sink is visible for inspection, 3) in the unlikely event of a blockage in the DW drain hose, getting to the high loop on the side of the DW would require removal of the DW, where getting to the undersink high loop is easy.

There is one more thing I forgot to mention. We don't want to use an air gap for the reasons I'm sure you have heard often. However, we did make a hole in the granite countertop for a soap dispenser (currently installed) OR an optional air gap (should we decide to install one later). I have the matching air gap ready should that become necessary in the future, for inspection or whatever. I have talked to a lot of people around here and it's not clear if code requires it or if inspectors get stuck on it (or if anyone really cares). So, having the air gap ready to install is "just in case". Given this set-up, removing the loop from the side of the DW and putting the loop under the sink seems like the obvious choice. If it ever becomes an issue, we just remove the undersink high loop and install the air gap. BTW, the drain goes to the disposal if that makes any difference.

I don't think it's a good idea to have 2 loops, even if you could do it with a 10 foot drain hose. :eek:

I was reluctant to remove the loop from the side of the DW without knowing exactly why they put it there. I now suspect they do that so that if the installer does nothing else but attach the hose to a sink or disposal drain, at least there's a high loop there even though it's not optimal.

I hope that our answers put your mind at ease about air gaps. I favor high loops because we have never had a complaint about one where we get complaints nabout countertop air gaps all the time. A counter top air gap's required if you live on the West Coat and fall under UPC. I would only use one loop on my installation. Good luck and thank you for rating my answer. Tom

Well, the hose that came with the DW can't flex enough to go directly through a hole at the bottom, and even if it could, it's 10 feet long which is a problem. I couldn't find a replacement drain hose, and it turns out I don't have much clearance for a hole near the top of the cabinet. So... I'm considering leaving the built-in high loop on the side of the DW and running the hose through a hole near the bottom. Now, I'll still have too much hose so I'll probably strap it up near the top of the cabinet before it goes to the disposal. This means I will actually have two high loops. Does anyone have a problem with that? Having a built-in high loop with a second high loop under the sink doesn't seem much different than having a built-in loop with an air gap. They both go to the underside of the countertop after the built-in high loop. The pump must be able to handle it, otherwise the manufacturer would include instructions to remove the built-in high loop when using an air gap.

Garya505: When are you going to tell us the name brand of your dishwasher ? :-D

Well, the hose that came with the DW can't flex enough to go directly through a hole at the bottom,
What bottom? The hose loops up to the top of the counter top bottom and back down into a disposal or branch tailpiece (see above image of a high loop). Why are you making it so complicated?

, I'll still have too much hose so I'll probably strap it up near the top of the cabinet before it goes to the disposal. This means I will actually have two high loops. Does anyone have a problem with that? I do! With two loops you will have built yourself a trap and when the DW pump shuts off youwill be left with a portion of the hose filled with dirty water. Suggestion; make a hole at the top, undo the built in high loop and make your own, If the hose is too long cut off the excess.
If you study the high loop diagrams and follow them you'll be just fine. Good luck, Tom

Garya505: When are you gonna tell us the name brand of your dishwasher ? :-D

Maytag MDBTT60AWW

What bottom? the hose loops up to the top of the counter top bottom and back down into a disposal or branch tailpiece (see above image of a high loop). Why are you making it so complicated?
I do! With two loops you will have built yourself a trap and when the DW pump shuts off youwill be left with a portion of the hose filled with dirty water. Suggestion; make a hole at the top, undo the built in high loop and make your own, If the hose is too long cut off the excess.
If you study the high loop diagrams and follow them you'll be just fine. Good luck, Tom

Your diagrams are great, but they don't address the problem of the built-in high loop on some late-model DWs. This Maytag MDBTT60AWW comes with a 10 foot hose, a Maytag 6916048, which is a plastic non-kinking type drain hose, and you can't shorten this type of hose.

The Maytag MDBTT60AWW has a built-in high-loop on the side of the unit. This takes the hose to the top of the DW, very near the underside of the countertop. Only the upward part of this loop is attached to the DW. The instructions that come with the unit are very poor.

The hose is too long to connect as shown in your diagram. I wanted to replace the hose so I got another DW drain hose (6 feet) from Lowe's, but the drain outlet on this DW is 1 inch diameter and the connection on the hose is smaller so I'd have to really stretch the connector to get it on. Yes, I'd like to run the hose through a hole near the top of the cabinet and shorten the drain hose as you suggest, but it's the plastic non-kinking type drain hose, a Maytag 6916048. It's easy to find pics of this hose (I don't know how to post pics here), and if you look you'll see what the problem is.

Yes, that hose can be shortened as installation requires.

Yes, that hose can be shortened as installation requires.

I'd love to shorten it, but it's the non-kinking corrugated plastic type, and there's a warning printed on the hose not to cut the corrugated section. The disposal connector can be cut to fit. The connectors are moulded on.

If Mayag had a 6 foot hose with these same connectors that would be great. The DW end is about 1 inch and the disposal side is the usual 7/8.

To make matters worse, the DW drain outlet is pointed toward the right front corner of the unit, so the hose has to make a sharp turn immediately after the connection. Making my own hose would be tricky, unless I can find a rubber 1-inch I.D. 90 degree elbow!

The Maytag MDBTT60AWW seems to be the same as the Jenn-air JDB4000AWW. The installation instructions are identical for both, and they show the built-in loop on the side. They also show the hole for the drain hose at the BOTTOM of the cabinet and then a connection to the disposal, which would create a trap.

OK, so I decided to use the stock 10-foot DW drain hose, leave the high-loop on the side of the DW, then run the hose through a hole on the side of the cabinet at the top (near the underside of the countertop). OK, so far. However, I will have about 6 feet of hose left and I only need about 2 or 3 feet to get to the air gap or disposal. So what do I do with the extra hose? If I loop it downward or let it go to the bottom of the cabinet, this will create a trap (remember I already have a high-loop at the DW). So, should I run the excess hose along the underside of the countertop, near the back of the cabinet next to the sink, before I attach to the disposal? The basic question is, should I keep the excess hose up high or let it go lower before going to the disposal?

The basic question is, should I keep the excess hose up high or let it go lower before going to the disposal? If you can't get another hose to work then keep the hose up high to avoid a trap. Good luck, Tom

OK, here's what I did, for the benefit of others who might have this same situation.

The DW is on the left side of the sink cabinet. I really only need about a 6 foot DW drain hose but I couldn't find one to fit, and the supplied DW drain hose is 10 feet long and can't be shortened (it's the popular corrugated plastic type). The DW has a built-in high-loop on it's right side (near the sink cabinet). The disposal is on the right side of the cabinet. I just cut a hole in the left side of the cabinet as high as I could (near the countertop) and ran the drain hose through that. Then I attached the hose to the back of the cabinet along the underside of the countertop behind the sink. Since I had about 4 feet of excess hose, I made a nice gradual S-shaped curve in the hose, down to the disposal, making sure the slope of the hose was always downward towards the disposal. Most of the hose is strapped to the back of the cabinet to maintain this slope. The result of this is that I have a DW drain that I would describe as a single high-loop with 3-foot flat top, and no trap. The DW side of this drain is attached to the DW itself and goes straight down to the DW drain connection. The high section of it is about 3-foot long, nearly flat, and attached to the cabinet up behind the sink. The outlet side (to disposal) of the hose takes a gradual S-shaped downward slope to the disposal.

Seems to work fine and looks nice and professional. :D

I'll make a drawing later and attach to another post if I figure out how.