Shower valve rough in too deep

[mitchk]

Hello all, I am to the point where I need to rough in the shower valve. I realized that the delta shower valve is just a little too deep for my wall depth. My walls are 2x4s running long ways with 1/2 plywood on either side. So my total wall depth is 2.5 inches. If I mount the valve to the back plywood it will stick out of the finished wall 1.75 inches which is. 25 further then what the valve reccomends.

Does anyone have any suggestions on thinner shower valves or thicker trim pieces/ handles that would be fine with the 1.75 inches sticking out of the wall.

[Delos356]

You could do one like this : https://www.homedepot.com/p/MODONA-C...2X-A/305351183

[Rucker]

Originally Posted by mitchk

Hello all, I am to the point where I need to rough in the shower valve. I realized that the delta shower valve is just a little too deep for my wall depth. My walls are 2x4s running long ways with 1/2 plywood on either side. So my total wall depth is 2.5 inches. If I mount the valve to the back plywood it will stick out of the finished wall 1.75 inches which is. 25 further then what the valve reccomends.

Does anyone have any suggestions on thinner shower valves or thicker trim pieces/ handles that would be fine with the 1.75 inches sticking out of the wall.

Do you actually need a mixer valve? I thought I did but I have an instant water heater, and they run best with a single line to the shower head.

[HamSkoolie]

If your build allows the space simply build out around the location of the mixer until you have the right clearance. You could do it in a way that looks like an intentional design, maybe even incorporate a little soap tray under or over the valve.

[mitchk]

Worst case scenario I'm going to build out around the valve area but I'm hoping not to have to.

[mitchk]

Originally Posted by Rucker

Do you actually need a mixer valve? I thought I did but I have an instant water heater, and they run best with a single line to the shower head.

Oh really? So you just wouldn't have the option for a cold shower I guess haha.

[Rucker]

Originally Posted by mitchk

Oh really? So you just wouldn't have the option for a cold shower I guess haha.

Bus plumbing may not be the same as house plumbing.

I learned the hard way. I plumbed everything in, and my water heater would not kick on with a mixer valve-not enough water flow. I ended up ripping things out and redoing everything.

Thus my question about what kind of water heating you have. You know, to help you from making the same mistake.

[mitchk]

Originally Posted by Rucker

Bus plumbing may not be the same as house plumbing.

I learned the hard way. I plumbed everything in, and my water heater would not kick on with a mixer valve-not enough water flow. I ended up ripping things out and redoing everything.

Thus my question about what kind of water heating you have. You know, to help you from making the same mistake.

I have the Girard 2GWHAM Tankless Water Heater. I don't have the manual with me currently but I believe it has a .6 flow rate to turn on. The shower says a minimum of 1.2GPM flow rate. I would guess that the majority of that would be the hot water side thus being well above the .6? I might be missing something though. What are your thoughts?

[o1marc]

Originally Posted by Rucker

Do you actually need a mixer valve? I thought I did but I have an instant water heater, and they run best with a single line to the shower head.

The hot water is always a single line to the mixer and the head if no cold is added. How to adjust temp with only hot water going to it? If PSI is an issue, maybe a bigger pump is warranted. Mine are 2.5gpm, more than enough for tankless heater and head pressure.

[Rucker]

Originally Posted by mitchk

I have the Girard 2GWHAM Tankless Water Heater. I don't have the manual with me currently but I believe it has a .6 flow rate to turn on. The shower says a minimum of 1.2GPM flow rate. I would guess that the majority of that would be the hot water side thus being well above the .6? I might be missing something though. What are your thoughts?

The first go-around, that was my thinking exactly. However, even with my Shurflo 3.0 GPM pump just a few feet away from the inlet there was enough pressure 'flow sag' (or maybe pressure sag? not sure which, frankly) to prevent the unit from kicking on. Part of that may have been a backflow valve (which I removed). I could get the thing to turn on if I opened another faucet, and it would stay on when I turned the second faucet off but that was no way to run a rodeo. I have no idea if your unit is subject to the same issues.

Even after fixing the backflow valve problem, I couldn't mix. As soon as I opened the cold (to moderate the output temp I had set the unit to, a little higher than needed, just so I could mix it down) the unit would shut off and send a blast of cold water. I needed something that would ensure the water wasn't too hot, but would not leave me freezing, at least in the shower.
Now the setup is a 'thermostatic mixing valve'

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

set to just slightly below the output temp of the water heater. A single valve pulls from the mixer, set to a reasonably warm temperature just slightly below the output temp of the water heater, so the GPM output of the heater doesn't drop below the minimum threshold.

https://www.skoolie.net/forums/membe...ture27322.html

I am still testing it under different conditions to see how well the automatic mixer influences the water heater but so far so good.

The lesson for me is 'mock it up and test it before committing.'

[Ross]

Lowe's item no. 553400, or similar, would be shallow depth.

[Mercuric Mind]

Try your local plumbing parts store, They may have a "deep rough in" trim kit. it will give you longer trim plate screws, and handle extensions and associated parts.
Good luck.

[jazty]

Originally Posted by Rucker

Bus plumbing may not be the same as house plumbing.

I learned the hard way. I plumbed everything in, and my water heater would not kick on with a mixer valve-not enough water flow. I ended up ripping things out and redoing everything.

Thus my question about what kind of water heating you have. You know, to help you from making the same mistake.

I encountered the same thing.
While my tankless propane water heater is hooked up to a mixer valve, I only turn on the the hot valve and adjust the temperature control using the readily available knobs on the heater itself. Once I crack the cold side of the mixer valve the low-pressure shut off switch is triggered and the water goes 100% cold.