The high loop should be behind the DW.

You may not run the line through the floor, under the floor then back up. That is considered a temporary line and it must remain in the same room as the appliance, it may not pass through a floor or wall, however, there is about a 4" vertical space from the floor of the room to the floor of the cabinets (Toe Kick height). You may run the line on the floor under the cabinets then stub it up to the disposal port or tailpiece connecter under the sink. The only caveat here is that you will have to be carefull to tell your cabinet installers to cut a notch in the base of the cabinet walls for the line to pass through. That won't be a problem because they are all accustomed to doing it when requested.

Thanks for the info.

I just got off the phone with Miele Tech Support and they a high loop is not needed.

I understand that the unit has a built in check valve, but that seems really strange and contrary to what I thought should happen.

I am contacting them via email and going to ask them whether a high loop is:

(a) optional (no preference either way and whose presence doesn't negatively affect the installation)
(b) required (must be present)
(c) excluded (must not be present)

as I would like to get their response in writing instead of verbally. I'll post what they respond with when I get an answer.

It doesn't matter what they have built into the machine,,,the plumbing code demands a high loop....

What you're planning is a pretty horrible idea from a functional layout standpoint. Sure, in an older kitchen where you're trying to retrofit a DW in, you can't always get one in next to the sink, but the further away it gets, the more dripping on the floor, on the cabinets, and the more water damage to all of that will happen. If your layout can't have the DW next to the sink, then you need to chuck that layout.

lazypup:

Yes, I understand that and unless they say "No, you must not put a high loop in" (highly unlikely), there isn't an issue because one is going in regardless. I just want it in writing from their Tech Support so something stupid doesn't happen down the line (eg, "The reason your pump went is you have a high loop which goes against installation directions.").

hollysprings:

We originally were concerned about the placement, but realized it was a non-issue after living with a mockup for four months. Because this is part of a peninsula, even though it is moving two cabinets away, it is effectively only one cabinet away and still within the National Kitchen & Bath Association planning guidelines for dishwasher placement (Locate nearest edge of the primary dishwasher within 36" of the nearest edge of a cleanup/prep sink.).

Furthermore, where one would stand when unloading puts virtually no additional path for water to drip beyond where it would when the unit was next to the sink. There is ZERO additional floor exposure for drips and about 2 sq ft additional countertop exposure ... a countertop that would have been wiped down anyway after doing dishes.

The best solution would be to install a standpipe behind the DW.