# Moen Posi-temp



## OldPlumber (Aug 4, 2008)

Hi Gang,

I've got one that's got me stuck and wondering if anyone else has run into the same problem. The home is 4.5yrs old, all of the water piping is pex. There is a recirc system and I'm getting proper hot water (122 degrees) at every fixture through out the home except the master bath shower (2 independent shower valves and heads. Moen Posi-Temp) and the jacuzzi tub. The tub (independent hot and cold widespread roman tub type valve) is the end of the line and the piping comes from the shower prior to that. Again, the 2 lav's 8' away have proper hot water there.

The problem just started a few days ago where the customer is only getting luke warm water in not only the shower valves .. but at the tub. I've replaced both moen posi-temp cartridges which has done nothing to change the situation. 

There is good pressure on both the hot and cold side of the shower And the tub. There is mixing or tempering of the hot water happening somewhere. I was suspicious that it was one of the posi-temp cartridges, which is why I changed them both .. but this didn't change a thing ? I have not run the water with the cartridges out because they're recessed a little in the wall and It would get quite a bit in the wall if I did. I also am getting the same pressure (no drop) through out the whole rotation of the handle from cold through to the hot, but only luke warm temperature at full hot side setting.

Have any of you run into the posi-temp valves mixing through, or tempering on a recirc system ? BTW - I ran the hot side only on the tub valve (remember 2 handle valve and absolute end of the line) with nothing else on for 10 minutes and Never got beyond luke warm water ?

Any thought's .. suggestion's .. hint's .. guesses ?


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## rocksteady (Oct 8, 2008)

Is the recirc. on 24/7? Or, more importantly, was it running when you were there? Maybe they pulled the recirc. off of the hot line just before the showers and tub? 


I always use the little chrome sleeve to help divert water into the showers so I can flush recessed valves, maybe that would help? I also swap out all my old Moen carts. for new at my wholesaler so I'd just throw another pair of carts. in there for kicks. Stupid question but these valves don't have integral stops do they?






Paul


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## DesigningWoman (Dec 17, 2010)

Hey OldPlumber – just a thought. Are the temperature limit stops properly set? If the cold water supply temperature has changed, the unit will need to be readjusted. Similarly, if the recirc was pulled off, the stops may need to be properly reset. 

Best wishes and please let us know what happens.

DesigningWoman


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## SlickRick (Sep 3, 2009)

DesigningWoman said:


> Hey OldPlumber – just a thought. Are the temperature limit stops properly set? If the cold water supply temperature has changed, the unit will need to be readjusted. Similarly, if the recirc was pulled off, the stops may need to be properly reset.
> 
> Best wishes and please let us know what happens.
> 
> DesigningWoman


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We look forward to your valuable input.


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## plbgbiz (Aug 27, 2010)

How long have the valves been in? When did the customer notice the problem? Do they ever get hot water or is it always just warm?

The temp limit stop would be the first thing I would check. It's a common miss for many a plumber when installing a valve or new cartridge. Aside from a direct hot/cold cross connection, it seems it must be something with the cartridges. If everything else has hot water, it all still points back to the cartridges.

I'm not sure how the valve having stops would affect temperature. I don't think the circ line is an issue either. Assuming it is not crossed into a cold line, where it returns from shouldn't matter.

I vote cross connection or limit stop.


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## beachplumber (Feb 7, 2010)

the roman tub not getting hot is perplexing. If it all worked before there must be something that has changed the situation. Ant outside hot and cold that could be cross connecting.


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## liquidplumber (Dec 6, 2009)

Don't forget to check washing machine they are known to cause cross connections.:yes:


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## RealLivePlumber (Jun 22, 2008)

Is there a tempering (mixing) valve serving the roman tub?

We are required to limit the temp to ALL tubs now. Lots of guys just bury them under the tile deck, with no acces.


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## Optimus Primer (May 20, 2009)

nevermind


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## ranman (Jan 24, 2010)

is the recirc. system piped? or is one with the bypass under the sink?


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## ap plumbing (Nov 9, 2010)

If there is angle stops under tub, check them to see if hot water comes out of angle stop:thumbsup: , or you could pull cartridge . Turn the water on and see if there is enough hot water coming out the shower valve. Just don't flood the place.Then you'll know if its the cartridge or not. :thumbup:
One time I had to change a shower valve because cross connection. Customer had hot water in her toilet tank.:laughing:


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## dclark (Dec 12, 2010)

I'd look towards the recirc.
If there is a check valve one the recirc line, it may not be closing. Re-re.
If there is not a check valve, I'd install one.
I had a similar issue..

The house has 2 Lennox Complete Heat units, mixing valves on both tanks, common hot water supply to the whole house, and recirculation returned to the cold inlet of one of the tanks, installed without a check valve.

The customer started to have issues with the ensuite shower 2 floors above, lukewarm only. I could only assume that the recirc was tied in adjacent.
2 visits later (I was busy and had limited time), after looking in vain for a cross connection (shower valve diaphragm, laundry, H&C hosebib, etc, I ended up installing a properly sized recirc pump c/w aquastat and timer, and a check valve.

I also corrected a few piping issues with the recirc return location / heat trap / mixing valve piping.

The initial cause could have been cold water bypassing through the unchecked recirc line as the pump lost effectiveness, or cold water bypassing through a mixing valve, or a little of both.

Regards

Don


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## 422 plumber (Jul 31, 2008)

Or the stem on the posi-temp cartridge needs to rotate 180 degrees.


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## dclark (Dec 12, 2010)

Reversed positemp cartridges result in 'hot then cold' instead of 'cold then hot'.
Handy for back to back rough-ins, but reversed cartridges won't result in mixing down of hot water or bypassing of hot and cold to downstream fixtures.


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## dclark (Dec 12, 2010)

Woops, that should read..
Reversed positemp cartridges result 'cold then hot' instead of 'hot then cold'.

Long week, i think my brains cartridge is reversed.


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## dclark (Dec 12, 2010)

nevermind...


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## 422 plumber (Jul 31, 2008)

dclark said:


> Reversed positemp cartridges result in 'hot then cold' instead of 'cold then hot'.
> Handy for back to back rough-ins, but reversed cartridges won't result in mixing down of hot water or bypassing of hot and cold to downstream fixtures.


wanna bet?


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## dclark (Dec 12, 2010)

Not a chance, I'm wrong on an hourly basis.


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## Richard Hilliard (Apr 10, 2010)

Check the re-circulating pump. I have had this very thing happen with Grohe,Delta,Kohler and it was a faulty re-circ pump.

When I was in Ohio I had this happen with allthe fixtures. We put hot and cold frostfrees in the garage and I found a y connection that a home owner installed to use one hose to wash thier cars and leave the hot and cold frost frees on using the hose nozzle. But again this wouod affect all fixtures.


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## DUNBAR PLUMBING (Sep 11, 2008)

I'm removing a Moen kitchen faucet I installed 3 months ago that leaks, sings, and thumps. LMFAO!! 



And yes; flushed the lines well before installing. 

At least I'm getting paid for someone not listening to my first recommendation, Delta.


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## Redwood (Sep 8, 2008)

fftopic: Heck for that matter wrong room! :laughing:


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## trick1 (Sep 18, 2008)

I had a defective valve body once that had a hole worn through it.

It was a double shower and there wasn't a velocity issue since that was the first thing that I thought of.

A hole formed and created a nice little cross connection that no cartridge would've taken care of.


If you notice a little cold water lag on the cold side of your fixtures being affected, this may be an avenue worth pursuing.


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## OldPlumber (Aug 4, 2008)

Thanks for all of the replies, sorry I didn't get back sooner ! 

There are no integral stops on either valve. The homeowners have lived in this home since new 4.5yrs ago. There is 122 deg hot water instantly at all other fixtures in the home including the 2 lavs in the master bath 5' away from the shower and tub. I double checked both cartridges that I put in to make sure they're in correctly. The cold comes on 1st and moves to hot where I'm only getting luke warm water tops. The handle stop limiters are set for full hot water, and I have full handle travel. The tub valve is a 2 handle (separate hot and cold handles) valve.

No piping work has been done on this home since new. The recirc pump was on and running when I was there .. now the 1 thing I did notice was corrosion on the outside of the check valve which is there and installed properly. The puzzling thing for me is that I'm getting Very hot water at all the other fixtures .. except .. the 2 shower valves and the tub ???? How would it be possible for everything else to get instant 122deg hot water if the check valve or recirc were defective ? Remember everything was working fine until 1 day last week and the next day .. only luke warm in the shower and tub .. which are at the end of the line.

The idea of a pinhole leak integral inside the valve is one possibility .. but it would have to be a decent sized hole to mix it down that much .. and how or why would that be affecting the tub ??? 

In over 33yrs of doing service this one may very well end up my #1 WTF !?!?!?! :blink:

Any new thoughts ?


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## SlickRick (Sep 3, 2009)

You have to be crossing over somewhere. Have you checked the washing machine or anything similar near by. I had a similar situation on one of the tankless units I installed a couple of weeks ago. I finally found the bleed over.


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## OldPlumber (Aug 4, 2008)

Reading back through some of the comments here .. I'm wondering if there is a mixing valve buried in the wall prior to the shower and tub ! If it's gone haywire that would explain everything !

Only problem now is that it's a tiled enclosure on an exterior stucco wall and I doubt there's an access panel ! What was that camera with a flexible tube lens in another thread ? I might need one now.


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## OldPlumber (Aug 4, 2008)

Hi slickrick,

The washing machine is 4 fixtures before where my problem is at. The recirc system is a piped system with no manifolds under the sinks (I've checked them ALL ).

Like I said in the last post I'm beginning to think there's possibly a mixing valve buried in the wall just prior to the shower.


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## SlickRick (Sep 3, 2009)

A mixing valve that was not accessible for maintenance would be a problem alright.


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## OldPlumber (Aug 4, 2008)

I think I'll move in that direction next. I'll keep you guys updated.


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## OldPlumber (Aug 4, 2008)

Oh Ya ! Thanks everybody .. it's nice when the old light bulb comes on ? I'' let you know how it turns out.


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## SlickRick (Sep 3, 2009)

Mine turned out to be a apparatus they had installed to make sure the horses had the right temp. water to drink when it was cold outside. I had hot everywhere but at the tub filler due to the volume it moved.


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## RealLivePlumber (Jun 22, 2008)

OldPlumber said:


> Reading back through some of the comments here .. I'm wondering if there is a mixing valve buried in the wall prior to the shower and tub ! If it's gone haywire that would explain everything !
> 
> Only problem now is that it's a tiled enclosure on an exterior stucco wall and I doubt there's an access panel ! What was that camera with a flexible tube lens in another thread ? I might need one now.


That's what I was sayin.......

Maybe they piped in for the shower after the tub, and they are both served by a tempering valve. 

I can't believe that the powers to be make us limit the temp into a tub. By the time you get a soaking tub full with 115 degree water, it's too damm cold to get into :yes:


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## SlickRick (Sep 3, 2009)

What was the problem, or are they still taking cold showers?


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## Pipe Rat (Apr 5, 2009)

My money is on the recirc and/or check valve. Problem fixtures are all at the end of the run where the return line line is most likely tied in at. Check valve fails and the water is finding a path of least reistance through the return line. Maybe not doing this for the lavs as they are further away and their water is following the normal path.

Heres the quick and dirty test.......... Let the system set static long enough to stabilize the temp of the return line. Now hold your hand on the check valve (or you more techical types can use an infrared thermometer :thumbup so you can feel the temperature of the check valve while someone else opens the suspect faucets. You will feel the temp drop if you are bleeding backwards through the return line. Don't assume either that just because the pump was running that it would be impossible to flow backwards through it given enough pressure or even broken vanes on the impellar.

In fact your best not to assume anything is impossible based on certain observations. Go in with eyes wide open to anything and eliminate ALL possibilities methodically.

Many times I have ended up taking the long path to solving a problem because I went in initially with my mind already set on what the problem *COULDN"T *be. :yes:

I'll take $50 on the check valve w/ 2 to 1 odds :thumbup:


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## SlickRick (Sep 3, 2009)

I'll take it for $20.00. I hate to pass up 2 to 1 odds.


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## Pipe Rat (Apr 5, 2009)

Your on for $20 Rick :thumbup: (as Pipe Rat and Slick Rick shake cyber hands):thumbsup:


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## OldSchool (Jan 30, 2010)

Its funny slick actually though he was betting on me ....

Your losing it Slick :laughing:


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## SlickRick (Sep 3, 2009)

OldSchool said:


> Its funny slick actually though he was betting on me ....
> 
> Your losing it Slick :laughing:


I really hate when that happens.


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## sigshooter71 (Dec 8, 2010)

It sounds like a mixing valve. I have had this before with mixing valves under jacuzzi tubs. & shower mixing valves. Sometimes it will affect one or more fixtures.


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## SlickRick (Sep 3, 2009)

sigshooter71 said:


> It sounds like a mixing valve. I have had this before with mixing valves under jacuzzi tubs. & shower mixing valves. Sometimes it will affect one or more fixtures.


I sure hope so. $$$$


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## OldPlumber (Aug 4, 2008)

I'm back with an update. No mixing valve installed in system. It's now down to the check valve, or recirc pump. 

I put in 2 new cartridges in the shower valves (just in case) and still only got luke warm water in both the shower valves and tub. Then I shut the ball valve on the recirc system and Ta Da .. we've got 122deg water in both again ! I'll be going out next week with a new check valve and recirc pump (just in case) to install. I'll start out with replacing the check and see what happens from there. 

Pipe Rat may turn out to be the winner here ! Your comment: "Many times I have ended up taking the long path to solving a problem because I went in initially with my mind already set on what the problem *COULDN"T *be. :yes:" Is Exactly what I was doing Wrong ! At this point I feel like my mind was more up my A** !!!! I was thinking (HuH ?) how could it be the recirc or check valve when I'm getting 122deg at Every other fixture in the house ?!?!? Well .... the old saying "You learn something new everyday" certainly applies here !

I'll let you know what it ends up being after I'm done.

I hope Everyone had a Very Merry Christmas ! I sure as hell hope it turns out to be a Prosperous New Year for EVERYONE Too !!!!!!!!

Again .. Thanks to Everyone for all of the help !!!!


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## SlickRick (Sep 3, 2009)

OldPlumber said:


> I'm back with an update. No mixing valve installed in system. It's now down to the check valve, or recirc pump.
> 
> I put in 2 new cartridges in the shower valves (just in case) and still only got luke warm water in both the shower valves and tub. Then I shut the ball valve on the recirc system and Ta Da .. we've got 122deg water in both again ! I'll be going out next week with a new check valve and recirc pump (just in case) to install. I'll start out with replacing the check and see what happens from there.
> 
> ...


 
@#%$& !**^%$#@! Pipe Rat, PM me mailing instructions, your $20 will be mailed out tomorrow.


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## Pipe Rat (Apr 5, 2009)

WHEW!!!! I was sweating those 2 to 1 odds Rick :laughing: :thumbup::thumbup::thumbup:


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## SlickRick (Sep 3, 2009)

Mailed out today, be sure and report the income.


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## Redwood (Sep 8, 2008)

slickrick said:


> Mailed out today, be sure and report the income.


Are you sending a 1099?:laughing:


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## SlickRick (Sep 3, 2009)

Yeah, but it has more zero's on it.


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## Pro Plumber (Jun 16, 2010)

:thumbup:


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## Pipe Rat (Apr 5, 2009)

Got it today Rick so I won't have to claim it until next tax year. :thumbup: Thanks


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## SlickRick (Sep 3, 2009)

My wife ask me if I wanted to attach a note to my friend.


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## Richard Hilliard (Apr 10, 2010)

Danncing the jig here. Have a great year


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## Pipe Rat (Apr 5, 2009)

Richard Hilliard said:


> Danncing the jig here. Have a great year


I agree Richard, It's the first workday of the New Year and I already have an extra crisp $20 dollar Bill. :thumbup:


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