How to Change a Moen Shower Cartridge

As far as shower faucet brands go, few have the brand recognition that Moen has. And with that name recognition comes a reliable and durable product. That said, even the best brands have parts that will need replacing from time to time.

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Typically, if Moen shower valves begin to leak or malfunction, it’s usually as simple as replacing the cartridge. Thankfully, replacing a Moen cartridge is a fairly straightforward, streamlined process. Most single-handle Moen shower faucets use the same Moen shower cartridge replacement (#1222), so finding a replacement is also generally pretty easy.

Do you have a single-handle Moen shower faucet that’s malfunctioning? A shower cartridge replacement is most likely what you’ll need.

Things You’ll Need:

• Moen cartridge replacement
• Phillips screwdriver
• Hex or Allen wrench set
• Adjustable pliers
• Needle-nose pliers
• WD-40

Step 1: Shut Off the Water

Before changing out your Moen shower cartridge, it’s essential that you shut off your water supply. Most of the time, a shut-off valve for a tub or shower might be found in an access panel, either in the bathroom or on the other side of the wall. If you can’t find an access panel, it might be located directly under the floor in the basement or crawl space. If you’re still unable to find the shut-off valve, you will need to turn off the water supply to your home at the main shut-off valve. When the water has been shut off, open the faucet to release pressure from the water line.

Step 2: Remove the Handle

To replace a shower cartridge, you’ll first need to remove the shower handle. Using a hex or Allen wrench, unscrew the set screw to remove the handle. The set screw is usually hidden on the bottom of the handle. If you have an older model Moen faucet, you’ll need to use a flathead screwdriver to pry off the plastic, glass or faux-crystal decorative medallion covering the handle. When the plastic cap is off, use a Phillips screwdriver to unscrew and remove the handle.

Step 3: Remove Valve Components and Trim (If Necessary)

Once the handle has been taken off, remove the plastic key stop by unscrewing it with a Phillips screwdriver. Then, remove the plastic temperature limit and the metal stop tube by hand.

Typically, the shower valve cartridge should be fully accessible at this point in the process. If it’s not, you’ll need to remove the trim plate that sits behind the handle to cover the hole in the wall. To remove the plate, use a screwdriver and unscrew the screws that secure it to the valve assembly. Keep track of the screws, here, since you’ll need them when you reattach the trim plate later.

Step 4: Remove the Retainer Clip

Next, remove the cartridge retainer clip. This clip is a small piece of metal that’s inserted through the top of the valve to keep the cartridge in place. Using a pair of needle nose pliers, grab the clip and pull it up and out of the valve.

Step 5: Pull Out the Shower Cartridge

Using a pair of adjustable pliers, grab the shower valve stem and pull the cartridge out of the shower assembly. Usually, the cartridge will slide out of the valve with no issue, but if it’s stuck, you may need to add some lubricating oil like WD-40 to loosen it.

When the cartridge has been removed, take a good look at the shower valve. If you notice any signs of rust or corrosion, you may need to replace the entire shower valve assembly and possibly the surrounding pipes as well. Unless you have enough plumbing experience, your best bet is to hire a licensed plumber to handle the job for you from here.

Step 6: Install the New Cartridge

Once you’ve removed the old cartridge (and assuming your valve assembly is in good shape), the new cartridge should slide in without issue. Once it’s in, place the retaining clip back in place over the valve to secure the cartridge.

Step 7: Turn the Water Back on and Reattach the Handle

Once the cartridge has been replaced, turn your water back on to test for any leaks. If none are detected, continue with the rest of the reassembly. Start by reattaching the metal stop tube, as well as the plastic temperature limit. The temperature limit allows you to adjust the temperature range of your shower. The number of splines you move will depend on how much restriction you want. If you'd like a hotter shower, move the outer plastic pieces to the left a few splines. It’s a pretty simple process, but you may have to test it a few times before you get it just right.

To turn it down, move the splines to the right. Once you have the temperature range set to your ideal preferences, you can use a Phillips screwdriver to reattach the plastic key stop. From there, reinstall the handle by replacing the set screw.

When the handle and trim have been reinstalled, test the shower handle for functionality. Note the water flow and temperature control. If all seems correct, you’re done!

Shower Time

A warm shower at the end of the day is one of life’s simplest pleasures. However, that sacred and relaxing daily ritual can be negatively impacted if the shower valve is leaking or broken in some way. The good news is that most valve issues can be solved with a simple shower cartridge replacement. As long as you don’t run into any rust, corrosion or other problems along the way, you can likely complete the shower cartridge replacement without having to call in a plumber to tackle the job.