Originally Posted by rebuilder
that is the problem the drain on the shower is just about as far under the shower as it can get
that is why i was hopig someone had some experience with them
You don't necessarily have to install the valve under the shower close to the drain. If, for example, the shower drain line runs to the vanity drain line, you can just put a 90 under the shower drain and run the pipe from there into the vanity and locate the valve there.
In case you aren't aware, the Hepvos are self venting; you do not need a drain vent when using those. You still need to run vent pipes for the holding tanks.