# Quick DIY Question - Shower Valve



## Inner10 (Mar 12, 2009)

I'm about to install a Moentrol shower valve and before I put the torch to it I had a vision inside my head of the guts melting.

Is it necessary to remove the balancing cartridges before I stick the heat to this valve?


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## Tech Dawg (Dec 13, 2010)

Make sure the cartridge is removed, although I've never had to remove the mixer...
Another suggestion, consider taking the Moentrol back and going with the PosiTemp valve with shut offs... the moentrol will cause banging pipes with the quick close cartridge and the mixer design on those are horrible that it is off to the side of the cartridge port, it creates too much back pressure.
I've had much better results with the PosiTemp:thumbup:


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## KillerToiletSpider (May 27, 2007)

Inner10 said:


> I'm about to install a Moentrol shower valve and before I put the torch to it I had a vision inside my head of the guts melting.
> 
> Is it necessary to remove the balancing cartridges before I stick the heat to this valve?


Is it a Moentrol or a posi-temp? There is a difference. If it is a posi temp removing the cartridge is all you need to do, if it is a Moentrol you need to remove the cartridge, and the balancing spool that is on the right side of the valve next to the cartridge.


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## superseal (Feb 4, 2009)

Tech Dawg said:


> Make sure the cartridge is removed, although I've never had to remove the mixer...
> Another suggestion, consider taking the Moentrol back and going with the PosiTemp valve with shut offs... the moentrol will cause banging pipes with the quick close cartridge and the mixer design on those are horrible that it is off to the side of the cartridge port, it creates too much back pressure.
> I've had much better results with the PosiTemp:thumbup:


Hey Tech, I forget...Is the Monticello a posi or moentrol? I have that in my bathroom and am not too happy with the performance. Don't hold back if it's a piece of crap. 

Killer - you can chime in too :thumbsup:


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## Tech Dawg (Dec 13, 2010)

Monticello used to be just with the Moentrol valve (I think)
Now you can get the trim with either valve...


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## Inner10 (Mar 12, 2009)

> Another suggestion, consider taking the Moentrol back and going with the PosiTemp valve with shut offs... the moentrol will cause banging pipes with the quick close cartridge and the mixer design on those are horrible that it is off to the side of the cartridge port, it creates too much back pressure.


Really eh? Obviously I know about as much about plumbing as I do gynecology. The only reason I bought the Moentrol is because a plumber who subs for one of the same companies I do told me it was a good quality reasonably priced valve. 

Instead of doing the positemp with shutoffs could I install water hammer arresters? I've also seen plumbers put a big tall piece of pipe vertically on both sides of the inlets to reduce "water hammer"



> Is it a Moentrol or a posi-temp? There is a difference. If it is a posi temp removing the cartridge is all you need to do, if it is a Moentrol you need to remove the cartridge, and the balancing spool that is on the right side of the valve next to the cartridge.


Excellent thanks! Definitely a Moentrol. Just like this:












> Hey Tech, I forget...Is the Monticello a posi or moentrol? I have that in my bathroom and am not too happy with the performance. Don't hold back if it's a piece of crap.


Super you can get it in either one, if I understand correctly with the positemp you rotate to turn on and adjust temp, moentrol you rotate to adjust temp then pull the lever to open/close the flow of water.


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## Tech Dawg (Dec 13, 2010)

PosiTemp is the turn style and the Moentrol is a push/pull... I have already had to tweak cartridges on the Moentrol because sometimes they float back in and shut.
If you have problems with the valve or a service (moentrol) there is no way to pinpoint anything because the cartridge is separate from the mixer whereas the Positemps is all in one and less parts to carry or shop for


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## Inner10 (Mar 12, 2009)

> If you have problems with the valve or a service (moentrol) there is no way to pinpoint anything because the cartridge is separate from the mixer whereas the Positemps is all in one and less parts to carry or shop for


Its going into my washroom, therefor if I have a problem I'll just replace both the cartridge and mixer. 

I'm more concerned about the banging pipes....should I put those anti-waterhammer gizmos in?


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## Tech Dawg (Dec 13, 2010)

There's no way to tell ahead of time unless if house pressure is above 120... Id install it and see what happens when you pressure test and flush the valve. 
Most times you won't have a problem so don't worry too hard


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## Inner10 (Mar 12, 2009)

> There's no way to tell ahead of time unless if house pressure is above 120


120 PSI? I could screw on a pressure valve and check.


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## Tech Dawg (Dec 13, 2010)

Inner10 said:


> 120 PSI? I could screw on a pressure valve and check.


Not worth it... just install the valve... like I said, never had many issues but that valve has been known to invite banging pipes


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