Second photo

Third and final photo (Can't figure out how to put more than 1 photo in my post)

I'm barely dangerous on well systems, but I wonder what your pressure is in the house. You can get an inexpensive gauge to thread on a hose bib, ideally near the new bathroom, to see what kind of pressure you have (cold water). I also would see if you get any different results with flow in the shower if you turn the thermostatic valve all the way down (i.e. some sort of restriction in the HW side).

I'd also look into how far away the new bathroom is from the feed from the well and how it's tied into the existing system (valves not all the way open?). There's also the issue that, if you turn all this stuff on, the outlets could be consuming around 10 gpm and need 60+ psi. That's both a capacity and head (pressure) question regarding your well pump system.

Looking at your piping, the one thing that I notice is the two taps on your diverter valve that are tied to the overhead shower head (first photo). You should check into your valve (ideally you have the brochure) to see if there's a chance it's piped incorrectly.

We have a Hansgrohe that does this with one valve (thermostatic plus diverter). It was set up to potentially have shower, tub filler, and handshower/sprays from one valve. Since we just have the two outlets (2 showerheads), you had to pipe the third outlet to one of the others. Like yours. But there's always a (slight) chance that your Kohler diverter wasn't designed to work the way it's piped up.

Hope that helps point you in the direction of gathering more info.

Here is a link that might be useful: This may be your diverter valve

Wells come with certain limitations as to water usage. I don't know who designed that shower in the first place, but they should have told you that instead of just doing what you asked. You're never going to get a "hotel experience" without spending the money for a lot of extra infrastructure to make that happen. That means a much larger hot water supply and pressure tanks to support this addition, with the whole delivery system re-engineered.

First let me preface with I am a female and sometimes donâÂÂt understand the technical jargon about pounds per square inch and gallons per minute.

Thank you both for replyingâ¦â¦.THULL you are correct about the water pressureâ¦â¦really have never had much in the house. We have been here 40 yearsâ¦.after about 20 years the pump in the well was hit by lightening so we had the new one installed in the cellarâ¦..a little better. This new shower is on the second floor and far away from the pump. One plumber I had at the house suggested a booster in the cellar that is connected only to the piping that goes to the new bathroom. As an aside; we learned early on that when someone flushes the upstairs toilet; NEVER to flush the downstairs toilet at the same time as the downstairs will overflow.

Now let me address the diverter valve situationâ¦â¦this is interesting. When the install was occurring; I was sent to the plumbing supply house to pick up everything that had been ordered by the plumber (or maybe the contractor). When I came back; I heard the contractor and the plumber talking. The contractor wanted to know why there were 2 diverters when only 1 was needed. The plumber said âÂÂnoâ he needed the hand held on a separate one. Perhaps this is the problem. Also; in the 4 years since this has been done I have had lots of plumbers come through (no one wants to touch it) and one of the plumbers said he too did not understand the piping when I showed him the photos.

I have discovered though if you ask 3 plumbers you will get 3 different solutions so now I donâÂÂt want to have anything done unless I am CERTAIN it will work. Some plumbers say þ inch to ý inch is ok. Others say 1â to þ inch would have been better. Others question the 6 foot run from the diverters to the body sprays in the back of the showerâ¦.etc. etc. etc.

I have no problem replacing the diverters as long as I donâÂÂt have to break the tile and replace the piping too.

IâÂÂm sure I have the Kohler instructions. I saved everything and I will check on the design.

Hollysprings; you are correct! However; we told EVERY contractor before we did this remodel about the water pressure. We told the plumber before he even began. Everyone said âÂÂdonâÂÂt worry about the water pressureâ¦..itâÂÂs not a problem; even with a wellâÂÂâ¦â¦â¦obviously I know now they all just wanted the job. And I am so frustrated with this I WOULD re-engineer the whole delivery system if I would be guaranteed it would work. How sad is that?

Sounds like you need to adjust the pressure switch up on the pump and also check to see how much air you have in your tank. After that is adjusted and checked, then go from there.