Brainstorm session

[Jamesplumbing06]

Ok so I arrived at a house today. They have a moen. It has been installed for 1 week. Issue is that water dribbles out of shower head while only wanting tub spout to be running. Copper thru out house. First guy plumbed tub spout with crimp pex and pex elbow like you would with copper. So immediately I noticed tub spout spins in a circle. Crimp restricts flow. I have had this happen before. So I went to truck and removed the female fitting to valve and used expansion pex with an eared ell. Mounted eared ell in place and installed new make x male copper tube going into tub spout. Done this maybe a hundred times. Still did the same. Didn’t have copper eared ell so I used a shark eared ell and shark female to attach to valve. SAME THING. I know I am looking over something simple and it’s hust been a long week. Psi is at 85 no regulator. But the expansion eared ell has big enough to work at 98 psi on a house just last month. So somebody pitch me a few things. Valve is installed with square part of valve up. So it’s oriented correct. Unless that last dumby turned the clip upside down so the trim would match picture. But I going back Monday. Nobody living there and I need to think. Does it without spout on

 

[GReynolds929]

If the distance between the spout and the valve is to much the back pressure will cause the shower head to dribble. Especially with crimp or restrictive type connectors.

 

[Jamesplumbing06]

Ok it’s 6 inches away. I have send them with valve set in middle of vertical wall and spout dropping down 18”. And I have seen them 3” down. I removed the crimp and even changed on over to shark. Would the white sleeves inside shark bite be enough restriction to cause this? I gonna go back Monday without anyone over my shoulder. But would like some ideas I haven’t already went over in long paragraph above

 

[Mikey]

If it's a Posi-Temp, they say "Installation of this product at non-recommended measurements may lead to issues such as water discharge from the showerhead during tub fill mode."

Recommended measurements are:

From bottom of tub to valve: 32"
From valve to tub spout: 6" to 11"
From bottom of tub to shower: 78"

Other than that, all I can suggest might be some crud in the valve restricting flow to the tub. Wouldn't take much.

 

[Jamesplumbing06]

Thx Mickey. Never noticed that installation. Measurements but I would say it’s close by memory. I am 6’3” so when sitting on tub edge the spout is knee high and valve is elbow high head is 6” from 8’ ceiling. I have installed a many positemps and love them. I will check that first Monday. I know I overthinking so I am looking for simplified responses.

 

[Mr_David]

I'm guessing it's a combination of both 85 psi water pressure and the pex pipe.
Does the valve have integral stops?
Positemps don't have any volume control. Turning it on pretty much full volume.
Maybe throttling down the 1/4 turn stops or just change the pex to copper.

Not Really sure what you mean by
" removed the female fitting to valve and used expansion pex with an eared ell. Mounted eared ell in place and installed new make x male copper tube "

 

[Mikey]

Just found this on another plumbing site from the site's owner, who's pretty-well respected:

"Always; if you have a tub/shower, you will need to run copper to the tub spout and not PEX."

I suspect the fitting would be the problem, especially if it's a crimp type, since PEX tubing flow rates for a given pressure are generally higher, but the crimp-type fittings have a smaller ID than the expansion-type.

 

[Rickyman]

Just found this on another plumbing site from the site's owner, who's pretty-well respected:

"Always; if you have a tub/shower, you will need to run copper to the tub spout and not PEX."

I suspect the fitting would be the problem, especially if it's a crimp type, since PEX tubing flow rates for a given pressure are generally higher, but the crimp-type fittings have a smaller ID than the expansion-type.

I found it in the installation instructions.

 

[Mikey]

Good catch. Somehow I missed that -- maybe because it was labeled "IMPORTANT" in my installation instructions.

 

[Jamesplumbing06]

ok Thx guys. I figure it out tomorrow. Y’all have a good Sunday

 

[Haworthplumbing]

Check to see if the rough in is upside down. I have seen it installed upside down and water came our both head and spout.

 

[Mikey]

Check to see if the rough in is upside down. I have seen it installed upside down and water came our both head and spout.

I've seen that where the hot and cold supply lines were reversed and the installer thought he would compensate for that . The valve has an "UP" cast into the upper side of the center section.

 

[Jamesplumbing06]

I definetly gonna check that. Thx.

 

[Jamesplumbing06]

Ok figured it out and I should’ve known. But yes those white sleeves inside sharkbite for grey pex. Took those out and everything works as normal. So just the finest restriction causes this. But I did keep the pex.couldn’t even use type a fittings. Thanks for everyone’s attention.

 

[Mikey]

Why couldn't you use Type A fittings?

 

[Jamesplumbing06]

I dunno I guess just enough restriction at the erred ell. But that was my first fix since its on my truck

 

[TomFOhio]

James, are you saying you pushed the pex back in the sharkbite without the plastic sleeves???

 

[Jamesplumbing06]

Yeah. I know. My theory is. The eered ell has 3 screws holding it. And the valve is secure with 2 screws. So they aren’t coming apart. Long as the o rings hold up should be good.