Shower head leaking when tub faucet is on

[Coopatroopa]

I'm remodeling my bathroom and have run into a problem. When i open up both hot and cold valves all the way and the tub facuet diverter valve is open, water comes out of my shower head. I originally thought it was due to using pex to the tub spout. I replaced the pex with 1/2 galvanized pipe and that helped, but the problem is still present. The attached picture shows how my plumbing is set up. The 4 way cross tee i'm using is here:

Since this is a custom setup (the volume control valves are sold separately, they aren't part of a complete kit), the cross tee is "generic", i.e. it is not necessarily made for shower plumbing, it did not include any type of restrictor to the shower head that is sometimes in complete kits. I did remove the little valve from the old faucet and jammed it into the brass cross tee, but that did not fix the problem. Any reason why the pex from the cross tee to the shower head would cause this? I would think not since it is smaller diameter and, if anything, would be a restriction compared to using copper pipe.

The only thing i can come up with at this point is to run a loop, similar to what is shown here:http://i.stack.imgur.com/kfXjq.jpg

Any thoughts? Thanks

 

[hj]

"4 way cross" is NOT the same as the center connection of a regular faucet. The reason a regular one operates is that it has a "restrictor" device where everything comes together to control the pressure in the shower riser. You do NOT have that restrictor so you have equal pressure going up tot he shower head as going down, and that is why the shower head leaks. There is NO cure other than to connect the shower riser to a "twin ell" at the spout.

 

[Sponsor]

 

[Coopatroopa]

"4 way cross" is NOT the same as the center connection of a regular faucet. The reason a regular one operates is that it has a "restrictor" device where everything comes together to control the pressure in the shower riser. You do NOT have that restrictor so you have equal pressure going up tot he shower head as going down, and that is why the shower head leaks. There is NO cure other than to connect the shower riser to a "twin ell" at the spout.

So, if i'm understanding this correctly, the twin ell would be installed as shown in the diagram below?

 

[hj]

yes, and and the top opening of the cross would be plugged. The shower comes off the rear opening of the twin ell.

 

[Coopatroopa]

yes, and and the top opening of the cross would be plugged. The shower comes off the rear opening of the twin ell.

Cool, thanks. I have one coming in the mail tonight. (Will report back later with the outcome.

 

[hj]

If it doesn't work, then you could mess up an iron ball with, your talents, or lack of them.
If the diverter spout does not come with it, remember, you need a spout with a 3/4" opening.

 

[Jadnashua]

Get rid of the galvanized nipple and replace it with brass now while you can, or you'll be sorry down the road.

 

[Coopatroopa]

Update: this fixed the problem! even with the 3/4" to 1/2' adapter that came with the twin ell i got no water coming out of the shower head with full water flow. Here is a picture for future reference. Don't mind that random couplings and bad soldering job, that was the previous home owner's gift for me.

I assume a brass nipple is preferable because it will corrode less over time?

 

[Jadnashua]

I assume a brass nipple is preferable because it will corrode less over time?

A brass one should last more than a lifetime, a galvanized one WILL start to rust...depends on how soon, but with the quality of many of those made in China these days, it could be months, not years or decades.