New diverter spout is restrictive even when open; lotta water goes up to the shower. Solutions without a shower head switch or a new valve?

[FlixFlix]

New tub spout (with diverter) is pretty restrictive even when fully open. It sends a good portion of water up to the shower. Is there any way to fix things without a shutoff switch on the shower head or replacing the Moentrol with a transfer valve?

Current setup:
½ Moentrol 20” above spout, 45” below shower = 65” (~5 ft) between spout and shower head. Unrestricted output is about 5 GPM.

Previous diverter spout was a free flowing cheap Danco. This new one immediately reduces the ½ NPT inlet to a ¼” opening and that plastic outflow grille doesn’t help either.

Are there any solutions without having to install a shutoff switch on the shower head or replacing the Moentrol with a transfer valve?

 

[WorthFlorida]

Nope, the spout 1/4" is the problem. Needs to be 1/2" copper.

 

[Sponsor]

 

[FlixFlix]

Nope, the spout 1/4" is the problem. Needs to be 1/2" copper.

Why would they even sell this product as a “tub spout with diverter” when it clearly can’t function as such. They should just call it “tub spout with shutoff valve”. Fml.

 

[Reach4]

Is that copper to the spout, is there any PEX in the path from the valve to the spout? I agree that the spout design is probably the main problem. I would call the manufacturer to report the problem. I don't know if they could provide a reworked spout with less restriction.

A shower diverter tee called a "twin ell" might do it for you if you have access thru the back.

Why is this plumbed this way? Grohe twin ell

I’ve seen some shower/tub plumbing where the tub faucet line is routed in a U (sort like a p trap) from the valve to the tub stub out. Why is this done that way in some cases?

www.terrylove.com

 

[FlixFlix]

Is that copper to the spout, is there any PEX in the path from the valve to the spout? I agree that the spout design is probably the main problem.

I’m redoing the shower wall. It’s currently all copper, but I’m redoing it in PEX, ¾ to the valve (a 2-way thermostatic), then ½ to shower head 1, and ¾ teeing into two ½ shared with shower head 2 and tub filler.

A shower diverter tee called a "twin ell" might do it for you if you have access thru the back.

I have full access to everything. That twin ell thing looks like one of those simple yet ingenious solution that takes a bit to understand… I’ll try my best!

I do wonder… can this be jerry-rigged using elbows and tees instead of waiting for the real thing from the slow gentlemen working at Kohler fulfillment?

 

[FlixFlix]

Ok so the right branch in picture 1 (the equivalent of a traditional shower/tub configuration) would definitely push more water up to the shower head compared to picture 2 which contains a jerry-rigged twin ell.

- Is there any static pressure difference between the two options?

- Could the dynamic pressure advantage of the twin ell configuration overcome the ¼” entry to the tub spout?

Or should I just forget it and put a shower 1 / shower 2 switch higher up the wall… which would mean you have to stand up to operate it.

 

[Reach4]

FlixFlix: Your second picture is clearly better, but my concern is the path between the tee and the copper. The second one puts less pressure up the pipe to the showerhead.

https://www.terrylove.com/forums/index.php?threads/no-way-to-do-pex-to-tub-spout.88719/#post-636336 is my suggestion for doing a diverter spout using PEX. However I am not totally sure even that would work with the spout you have. I am quite sure that if that spout works with all copper, then it would work with my suggested way. I think my suggested way is probably as good as a twin ell.

If your spout clamps to a copper pipe, and will not work with a brass nipple, then you could solder a MIP adapter to a copper pipe. The tee would have to be deep enough to let the adapter not interfere with the spout.

 

[Breplum]

The worst tub spout stub is copper. 1/2" FIP is ideal since it allows for changing spouts at any time.
Kohler specifically states in all the literature to NEVER use 1/2" PEX for diverter tub spouts due to restrictive flow.
as far as the 1/4" drilling on the spout it is definitely lame-brained crap. What mfr would do that?