I would like to replace the cartridge in my shower faucet handle with a pressure stabilizing one, so that running water in other parts of the house won't spike the temperature in the shower. The existing cartridge looks exactly like Moen model 1225. That replacement part doesn't say anything about being pressure stabilizing. Other Moen cartridges do though, for example this Posi-Temp one which is similar, but looks too large to fit in place of the 1225 model.

So basically I want the Posi-Temp functionality that can be used to replace a model 1225 unit. I have been to three different hardware stores without finding such a part, and the staff at each store has had no idea where I could find such a thing. I swear I did a replacement just like this some years ago, but I am really struggling to find the part I need. Any help would be much appreciated!

  • This is a shopping question, (find this unicorn part for me) and thus off-topic. The obvious solution if you can't find the unicorn part is to replace the whole valve body with one that does what you want. As for the unicorn part, call Moen, they can tell you if they make that particular unicorn or not.
    – Ecnerwal
    Commented Mar 12, 2023 at 14:47
  • @Ecnerwal sorry if I'm misinterpreting your love of the word "unicorn" but your comment seems unnecessarily condescending. An answer along the lines of "Try searching with this keyword" or "This is not a standard part" would have been sufficient.
    – rurp
    Commented Mar 14, 2023 at 22:00

1 Answer 1


The pressure balance cartridges fit only the newer designed Moen valves and cannot be fit into a first gen. unit.

First gen units have the screw boss for mounting the cover trim at the bottom only. ( 2 screws get attached near the bottom of the valve handle.) Later gen. units have screws diagonal at roughly the 1 and 7 clock position. There are conversion plates available that allow later gen. trim to be used with a first gen. valve. However I am not aware of any pressure balance cartridge conversion.

The bodies of the later gen. valve are larger in diameter to accommodate the larger size posi-temp cartridges. The posi-temp will not fit in a first gen. valve.

You can try to contact Moen to see if there is now a conversion. However I have never come across one.

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