Latest Discussions : Plumbing


08:06AM | 08/28/03
Member Since: 02/12/03
19 lifetime posts
Having vexed the fine people at Moen, I turn now to the collective wisdom of the B.V. Bulletin Board for thoughts on this problem.

A quick picture of the issue: New construction, 2nd floor, full bath. Brand new Moen Posi-Temp shower assembly. All copper pipes.

After installation (done by our plumbing subcontractor) turning on the water caused a steady stream of water to come out of the spout and a very steady flow from the shower head.

Plumber diagnosed that we had a water pressure problem. This was confirmed with use of a water pressure guage (90 psi). This problem was resolved with a pressure regulator. Now the house water pressure is about 50 psi.

Unfortunately, the shower problem persists. I spoke with the fine folks at Moen (we otherwise love their products) and confirmed that the distances from the valve to the spout and shower head were within the ranges for this product.

The Moen folks thought perhaps the cartridge for inside the valve was faulty. A replacement was sent and installed - still...same problem.

Exasperated, the Moen folks suggested perhaps the pipe from the valve to the spout had a blockage of some sort. We removed the pipe...looked insde with a flashlight, no blockages.

Any thoughts? Anything obvious we've missed.

In order to mitigate the problem, Moen sold us a very nice flow control valve for the shower head - this stop the water from coming out of the shower head, but there's still a trickle and frankly the flow coming out of the spout is not very strong (IMHO).


05:35AM | 08/29/03
Member Since: 06/30/03
2 lifetime posts
Unfortunately, I can only offer my experiences with the same thing. I bought a new tub spigot (not Moen) and installed it and had the same thing happen. So off to the hardware store to change for another one... Rats! Same thing! I asked everyone I could and got the same answer you got. Water pressure! But if that is so, why didn't my old spigot leak? My temporary solution was installing a shower head valve also. It seems to me that this ought to be an easy fix however nobody seems to know what that would be... I'll keep watching here for help gems...

erik peterson

04:28AM | 11/24/03
Member Since: 06/23/03
223 lifetime posts
Install what is called a "double-ell" between the valve and the shower riser (inside wall) this will take care of the must go to a professional plumbing supply store and make sure the clerk has the experiance to know what this device is (obscure these days, used to more common) erik


06:04PM | 06/20/15
I use pex pipe and shark bite fittings for many showers with success. The last one i plumbed i experienced the above problem. The shark elbow for the tub spout had a reduced opening inside and once i changed it and the pex for the spout only, no more problem. Diverted too much water up due to the restricted opening. I dont think the pex was the problem because it acted the same way after only changing that piece of pex for copper.


07:29AM | 07/24/15
change the valve up
side down


08:23PM | 07/25/15
The moderator will not allow me to give the correct answer as they keep blocking me from signing on.

Contact me Tieger plumbing my E mail is readily available and I will tell you how to alleviate the problem

Seems then new moderator does not like to be corrected


12:23PM | 01/14/18
Our Stacking issue fixed with above suggestion to remove the shark bite elbow and replace with copper fitting, leaving all other pex in place! Thanks!


06:44PM | 03/06/18
According to Delta Faucet, it is called shower rise. It is caused by the spigot discharge pipe being to short of distance from the valve body. According to Delta it has to have a minimum drop of 8" from the valve and no more than 18". Just installed a new Delta faucet and have the same issue and they said it was because of incorrect installation.
My drop is constructed of 1/2 copper pipe and is 7.5 from the valve to the elbow. I could not find anything in the faucet installation instructions that came with the faucet, but was told this by their HELP team. Unfortunately my new shower is ceramic and I will have to live with this issue. Or perhaps try to find a cut off valve to install at the shower head.


05:04PM | 03/10/18
Changed shower heads


05:04PM | 04/07/18
Sounds to me like the Shower valve is installed upside down. Been a Plumber for 24 years.


11:47AM | 04/29/18
Hi all - found this forum when trying to install a Moen INS2153C tub/shower valve, and experiencing "stacking", or flows from the shower head while the tub fill is running at maximum. My distance from the valve to the shower arm was the prescribed 46", the valve was installed proper side up/down, and the lines had been flushed prior to hookup.

While the inside diameter of Pex is the same as the opening in the tub spout (and therefore it seems like Pex should be OK), the actual flow capacity of the FITTINGS that Pex uses, is less than the flow capacity of the Pex pipe itself.

IMHO, the Engineering of valve assemblies like this one (any that rely on blocking the flow at the tub spout to activate diversion of the water to the shower arm), should be re-thought, given the popularity and ease of use of Pex.

My solution was to purchase one of the newer design shower panels, which require only a single standard Hot stub and a single standard Cold stub. I brought those out of the 4.5" circle I had cut for the Moen valve. These new models have the same type of connection as a sink tap, dead simple. Upside: 1) Nicer functionality (because the show panel has more choices of water flow; 2) No need to break into the wall and undo existing work; and 3) I finally understand why they say to use copper to the tub spout. IMHO this is a restriction that could be eliminated if the mixing valve manufacturers would re-think the existing design in light of popularity and ease of use of Pex. It's not like the panels are materially more expensive that the mixing value, certainly as a % of the bath reno project overall it's a rounding error.


06:47PM | 10/02/18
I am a master pllumber in Houston, Tx and have seen this problem present itself a couple of times. The 1st time the issues was that the installer used what we call a drop ear 90 to stub out the tub spout. This caused too much resistance causing water to back flush to the head. The 2nd time was that the spout distance was stub out too far from the valve causing the water to travel upward out the shower.


04:30PM | 04/08/19
I have this problem with a new Moen posi-temp, also (from model kit 82603). Valve to tub spout tube is: Shark-bite > Copper > Shark-bite 90 > Iron Pipe (PEX everywhere else). Valve drop to spout tube is within the 6-11 inch tolerance.

There is no stacking issue with the threaded spout uninstalled...

Moen support guy said valve must be 32 inches from tub floor (mine is 29). ??? >:(


09:05AM | 07/27/19
You need to use a volume control valve and it goes between the shower arm and shower head hope this helps


06:06PM | 11/21/19
THE VALVE IS UP SIDE DOWN! Call the installer back to fix at no charge! This is a common problem. take the handle & cover off it will say up on the valve it self . If the valve is in the correct position try replacing the stem. The distance makes no difference in the installation .


08:57PM | 11/21/19
Water runs out the showerhead when spigot with diverter bottom is inward position to fill tube. This a Adler moen shower and tub shower valve. The valve is in the up arrow position as shown on valve. I thought it might be the spigot. So I remove the spigot from the pipe. While running water through the pipe I notice showerhead was not leaking however, when I change the position from cold to warm with the regulator, the shower head began to run water out also. I am confused, some are saying that valve is upside down. While are saying spigot or cartidge is faulty. This a newly installed shower head. Has anyone, figured out the problem? Moen has no clue. I have a client who is highly dissatisfied. Thank you


09:52PM | 11/27/19
Try copper pipe from the sprout to the cartridge


08:57PM | 12/02/19
I just replaced the pex w/ sharkbite drop ear down spout with galvanized and the problem was resolved.


08:27PM | 12/09/19
From the school of hard knocks, I have had more quality and function issues with Moen fixtures than any other, and it infuriates me. You wouldn't believe the extensive trouble I've continually had with their faucets and tub/shower products. They have no problem giving you all the advice in the world and sending you free replacements, but no thanks, I'd rather have something of quality and intelligent engineering from the start.


10:15PM | 01/21/20

Thank you, BV020931. I just had old faucets replaced with Delta shower body, and when set for water to come out the tub spout, a portion comes out the shower head. Fortunately, have not yet re-tiled the wall, and I was able to look at the back of the valve with a mirror. Sure enough, the Up arrow was pointing down.


04:57PM | 02/26/20
We turn on the shower and water comes out but still a good flow from the spout, worked fine until we changed the handles , we did not change the spout and got a new shower head


09:46AM | 03/05/20
Installed a brand new delta shower and tub faucet. Water comes out both the tip spout and shower head. It’s not a bad diverted in the spout, I have changed that out three times. It has plenty of water pressure in the lines. So what gives? Very frustrated.

Leo Alfie

06:50AM | 03/06/20
Member Since: 03/03/20
36 lifetime posts
Try to change the showerhead.
but once it goes out of order then no other option to change it.
if you have pics then share it. maybe there is a chance to solve water leaking issue.


07:32PM | 04/30/20
What about installing 3/4" pipe to shower spout, thus reducing the pressure to the shower spout


08:42AM | 05/02/20
tub runs out of hot water after 5 minutes, not getting enough hotwater to tub use. Plus while running the shower, water leaks out of tub spout. any suggestions?


10:37PM | 05/14/20
Member Since: 05/14/20
3 lifetime posts
The problem of shower water pressure can be solved by replacing a high-pressure shower head. Moen has such a thing, but if Moen cannot increase the water pressure, then return it and choose a pressurized shower head of another brand. Some brands are not suitable for water pressure in your area.


08:24PM | 05/17/20
I just ran into this problem and it’s not just a simple answer like the valve is upside down.... I have had this happen twice and it’s a combination of to much pressure from the tub spout line and to many 90s. I solved the problem by going from the valve to the tub spout with only one 90 and 3/4 pex instead of half because of the back pressure. It really depends on the orientation of the valve as well to the tub spout and shower head because they can create back pressures based on the valve styles.


10:20AM | 06/10/20
Hi I'm managing a big building which is 30 years old, I never have this issue until now, start from few weeks ago I have already 7 showers leaking from shower while feeling tub, I took off the spout and the shower head and same issue, any help?


09:18PM | 07/01/20
I replaced an old faucet with a Pfister. We used PEX as supply lines, 1/2" copper as outlet. Discovered the water supply lines built with the house are reverse, so we used the back-to-back installation instructions and flipped the valve (so that when you call for hot water, you get hot water). I get a steady flow out both outlets at the same time.

We originally ran PEX as outlets and PFister told us that wouldn't work - in their minds, not showing how to do that in their instructions is the same as telling you not to do it. Switched to the copper and have the same trouble.

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