Moen Vertical Spa, when to change pipe diameter in multi-head shower

[WendyH]

My husband and I are doing a complete master bath remodel, including moving all fixtures and adding a steam shower. This forum has already saved our bacon a number of times in the planning and process. I have our plumbing code just about memorized, but you all have much better descriptions. We also went with a Toto after reading on this site.

I finally have a question I don't see already answered. We are going with a Moen Exacttemp shower system. There is one thermostatic valve and 3 volume control valves. All the valves are 3/4" as is the supply. All the shower heads have threaded 1/2" connectors. The pipes between valve and head will be running an average of 5 feet. Am I better off stepping down to 1/2" right after the volume controls, or should I run 3/4" almost all the way to the heads? And why? I'm using all copper.

[Terry]

Most of the time, these are run from 3/4" and then branch off individually to 1/2" for each head.
That way, you keep constant flow to each head in the group.

I have also seen it plumbed with a loop with 1/2 heads off of it to maintain steady pressure at each head.

Shower control instructions

Exploded parts view

Specs

Vertical Spa Installation Guide

[WendyH]

Thanks much. The install guide pdf is so much better than the one that came with the system. And it exactly answered my question. I'm not using body sprays, so thankfully don't have to worry about a pressure balancing loop.

I'm sure I'll have more questions before this project is done. Electrical work is so much easier for me than plumbing.

[Valerie]

Hi Terry,

Thanks for the great website. I have learned SO much from your site in planning our remodel. We're combining a 3/4 bath and laundry room (flipping washer/dryer/hot water heater to opposite wall, built into a new closet). It's a small space in a mid-century modern (read: fewer the frills, the better) and I want it to be functional, efficient, and GORGEOUS! My heart is set on the Moen Eva line for faucets and fixtures. I've considered the Moen vertical spa (without body sprays) but really just want a shower head and hand-held for the occasional 2-person shower - NOT for an all-the-time "spa experience". Cost IS a factor. Right now, the Mariner II is looking real good to me. I assume if they're in your store, they've met your standards and they're quality.

Here are my questions: 1) am I sacrificing performance for looks with Moen Eva? 2) Do I need anything besides a thermostatic valve and valve trim for the Mariner II? I don't see any dial in the picture on your online store. 3) Can I use the Moen thermostatic valve and Eva trim with the Mariner II?

I've chosen The Toto Aquia II for the bathroom, and think someday I'd be interested in a washlet. Would it be beneficial to do any modifications at the time of initial installation, future use in mind?

Do you stock both the Aquia and Mariner II in Bothell?

Thanks for your time.

[Terry]

Valerie,
Any of the standard shower valves will work with the Mariner II, I like Moen and Delta, it will work fine.
If I don't have the right finish in the Marinier II, it just takes a few days to be delivered on your door step.
I have plenthy of the Aquia II, in stock, they are on sale this month for $299.99
As far as a future Washlet, it uses the same water supply as the Aquia, you only need to add an electrical outlet.