Quick answer: A Posi-Temp valve is Moen's pressure-balancing valve with a 1222 cartridge: its single handle only rotates and sets the temperature, with no volume control. M-CORE is Moen's newer system, and one M-CORE mixing valve takes 2-, 3- or 4-Series trim: 2-Series controls temperature only, 3-Series controls temperature and volume with one handle, and 4-Series adds a separate volume handle to thermostatic temperature control. Moentrol (1225 cartridge) controls both: pull the handle out to turn it on and set the volume, rotate it for temperature. The M-PACT standard means the brass body stays permanently installed.
Almost every returned shower trim kit comes back for the same reason: the trim was built for a different valve than the one already in the wall. Moen sells trim and valves separately, and the two have to match. Before ordering anything from our tub and shower trim range, it is worth spending five minutes working out which valve platform you have.
Once you know which valve is in the wall, you can compare in-stock Moen tub and shower trim kits made for it.
Trim for each valve comes in several finishes: see in-stock brushed nickel shower trim kits, matte black shower trim kits and chrome shower trim kits.
The three names mean different things
They are often used interchangeably, which causes most of the confusion. They are not the same kind of thing.
Posi-Temp is a temperature control, not a product line
Posi-Temp is Moen's pressure-balancing mechanism. It keeps the shower at a steady temperature when someone flushes a toilet or starts a washing machine and the cold supply drops. A Posi-Temp valve is a single-handle valve whose lever only rotates: it sets the temperature, and there is no volume control, so the force of the water cannot be turned up or down at the handle.
An example in stock: the Moen T2262EPBG Cia Brushed Gold Posi-Temp Shower Only Faucet.
Posi-Temp valves use the 1222 cartridge. If you have ever replaced the cartridge in your shower and the box said 1222, you have a Posi-Temp valve.
M-PACT is the valve body standard
M-PACT is Moen's common valve platform. The idea is that the brass body stays in the wall permanently, and you can change the trim style years later without opening the wall or re-plumbing. The Moen 2385PF rough-in valve we stock is an M-PACT body with Posi-Temp pressure balancing, built around the 1222 cartridge, which comes with the valve rather than the trim.
So "M-PACT Posi-Temp" is not a contradiction. M-PACT describes the body; Posi-Temp describes how it controls temperature.
M-CORE is the newer platform, and it comes in series
M-CORE is Moen's more recent valve system, and this is where series numbers start to matter. M-CORE trim is sold as 2-Series, 3-Series and 4-Series, and the series decides what the handle does. A 2-Series handle rotates for on/off and temperature only. A 3-Series handle rotates for temperature and tilts up and down for on/off and volume. A 4-Series trim has two stacked handles: the inner, longer one turns the water on and off and sets the volume, and the outer, shorter one sets a thermostatic temperature. Our Greenfield UT4322EPBL, for example, is a 4-Series trim, while other kits are explicitly listed as designed for M-CORE 3-Series valve systems.
The series does not change the valve in the wall. The M-CORE cartridge (1212, 1213 or 1214) comes in the trim box, and Moen's specification sheets for 2-, 3- and 4-Series trims list the same U130 and U140 series mixing valves, so moving a 2-Series shower to 3- or 4-Series trim means changing the trim, not the valve; Moen confirms that a 2-Series to 3-Series upgrade does not require opening the wall. The exception is the M-CORE valve with an integrated transfer, which Moen offers with 3-Series trim only.
Moen's specification sheets name the valves each trim fits. For the Arris UTS32003BL, a 3-Series tub and shower trim, Moen lists the U130 and U140 series M-CORE valves; the U140XS we stock is one of them.
| Feature | Posi-Temp | M-CORE |
|---|---|---|
| Handle Control | Single handle that only rotates: temperature only, no volume control | 2-Series: temperature only. 3-Series: temperature and volume in one handle. 4-Series: separate volume handle plus thermostatic temperature |
| Cartridge or Valve | 1222 cartridge, supplied with the valve | 1212, 1213 or 1214 cartridge, supplied with the trim; U130 or U140 series mixing valve |
| System Age | Older installation | Newer platform |
| Trim Series | Not applicable | 2-Series, 3-Series, or 4-Series, all on the same mixing valve |
| Example Trim | Posi-Temp trim | UT4322EPBL (4-Series) |
How to work out what you have
In rough order of reliability:
- Find the original paperwork or the model number. If you know the valve model, everything else follows. Our guide to finding a Moen model number covers where to look.
- Check the cartridge. If a 1222 cartridge has ever been fitted, it is a Posi-Temp valve. A 1225 means Moentrol; 1212, 1213 and 1214 are the M-CORE 2-, 3- and 4-Series cartridges.
- Count the handles and what they do. A single handle that only rotates, with no way to change the volume, points to Posi-Temp or M-CORE 2-Series. A single handle you pull out to turn on and set the volume, then rotate for temperature, points to Moentrol. A single handle that rotates for temperature and tilts up and down for volume points to M-CORE 3-Series. Two stacked handles, an inner one for on/off and volume and an outer one for temperature, point to M-CORE 4-Series.
- Consider the age of the installation. M-CORE is the newer system. A shower installed many years ago is far more likely to be Posi-Temp on an M-PACT body.
- Take the trim off. With the water shut off, removing the handle and escutcheon exposes the valve body, which usually carries markings.
Do not guess
If you cannot confirm the platform, do not order on the balance of probability. Posi-Temp and M-CORE trim are not interchangeable, and within M-CORE the series decides whether you get volume control. Every listing in our trim kit range states the valve platform and series it is built for, and our valves and rough-in section lists the valve bodies themselves.
If you are still unsure after checking, send us the model number or a photo of the valve and we will tell you what fits.
Written by John Plumber, an experienced plumber who shares his personal opinion and hands-on experience.
This article reflects personal experience, not step-by-step instructions. Always follow the manufacturer's installation guide for your exact model, and hire a licensed plumber if you are not sure. Questions or corrections: support@aqualux.studio.
Related reading
