How to Replace a Shower Cartridge in 9 Simple Steps

Noticing a leak when you're taking a shower may not seem like a big deal at first—a shower’s designed to handle moisture, after all—but it’s something you’ll want to investigate. A broken shower cartridge can cause rust and erosion behind your shower valve. And over time, it can prevent your shower nozzle from making the water hot or cold. 

A shower cartridge can last anywhere from 10 to 30 years, so replacement won’t be a frequent occurrence. And as far as common shower problems go, this one's not too difficult to resolve and won't cost an arm and a leg. Here’s how to replace a broken shower cartridge in nine steps.

1. Turn Off the Water Supply

Before you begin, there are a few preparation steps. First, you need to turn off the water supply. You have two options for turning off your water before beginning the project, and your home's water setup will determine which to choose.

In most cases, you'll want to shut off your water supply at the main valve. Some showers have individual valves stationed behind the shower handle that you can shut off, so shutting it off there is fine if your shower has one. 

If you shut off the main valve, run the bathroom faucet for 30 to 60 seconds to relieve pressure and let the water in the pipes drain. Ask a local plumber or shower installer near you for help if this task feels out of your wheelhouse.

2. Cover the Shower or Bathtub Drain

Next, you need to shut and cover the bathtub drain. You can clog it with a towel or cover it with tape. This way, you won’t accidentally drop anything down there while working—an easy step with a huge potential payoff.

3. Remove Your Shower Handle

First, you'll need to remove the handle to see if the shower cartridge is the reason your shower is leaking. Use a flathead screwdriver to pry the plastic cap off the shower handle.

Every handle is a little different. If it's not apparent by looking (e.g., a screw is attached to the handle), do an online search for the make and model of your handle with the term "removal” to find instructions for removing it.

If your shower handle design is a single lever, you might need an Allen wrench to loosen the screw underneath and remove the handle.

4. Remove the Escutcheon

Next, you'll need to remove the escutcheon, the piece of metal shaped like a ring or sphere that covers the hole in your shower's wall and is attached to the wall with screws. Set it aside with all the screws for reinstallation later.

5. Remove the Retainer Clip Underneath

Behind the shower handle and flat metal plate, you should find a clip holding the shower cartridge in place. Again, different models will look different. Some are covered with a metal sleeve, while others are exposed. 

Use a flathead screwdriver to unhook the clip holding the cartridge in place. Set it aside in a safe place. While many new shower cartridges come with a retainer clip, some do not. If that’s the case, you can simply reuse the original clip. 

6. Use the Puller Tool to Remove the Old Shower Cartridge

Locate your shower cartridge pulling tool. If your model is older, you can simply remove it with pliers. Hook the puller tool onto the edges of the cartridge and slowly turn until it loosens.

Note the position of the cartridge before you begin unscrewing it. You'll need the new shower cartridge to be in the same orientation to ensure hot and cold water comes out the same way when you turn the handle.

7. Install the New Shower Cartridge

In some cases, a shower cartridge's O-rings may simply have mineral deposits on them that cause them to leak. You can try removing the mineral deposits and reinstalling the O-rings before buying a new kit. 

Otherwise, position the new shower cartridge into the vacant space. If your new shower cartridge comes with a model-specific tool for installation, use it. Make sure it's tight and in the same position as the old one was.

8. Turn the Water Back On, Then Test

Once the new cartridge is in place, turn the water supply back on and test your work. If there's still a leak in your shower, you may need to double-check that everything is tight.

If you still notice leaks but are confident it's not the shower cartridge—for example, maybe you notice only a few beads of water running down, suggesting that a pipe is loose or your shower is old—you might choose to reinforce the edges of your escutcheon and valve with silicone caulk. Read the directions carefully and adhere to dry times before retesting.

9. Reattach the Escutcheon and Shower Handle

Retrace the steps you followed earlier: re-install the escutcheon and screw the shower handle back on. To protect your new investment, consider adding a bit of plumber's grease to prevent erosion over the surface of your new shower cartridge. A tube costs $2 to $5 at home improvement stores.

When to Replace a Shower Cartridge 

A failing shower cartridge can cause various issues with the water flow or the shower handle. Over time, the cartridge can develop mineral deposit buildup, get damaged by corrosion, or break from long-term use. When the cartridge gets damaged or blocked, you’ll notice things like the water not turning off completely even when you turn the handle to the “off” position. Conversely, the water may not flow when you turn the handle to the “on” position. In other cases, your shower handle will get stuck, and it will be difficult to turn.

If you’re noticing some or all of these signs, it’s likely time to replace the shower cartridge. Keep in mind that the lifespan is 10 to 30 years, so if it’s been longer than that, it’s a good idea to replace the cartridge as part of your preventative maintenance plan.

DIY Shower Cartridge Replacement vs. Hiring a Pro

Replacing a shower cartridge yourself can be a bit of a challenge if you don't have plumbing experience. But doing so will definitely save money, as the parts to replace yours start at around $50. On the other hand, hiring a pro to replace your shower cartridge will cost between $200 and $400 for parts and labor.

So long as you aren't fearful that you'll break the shower (and you won't if you follow the steps outlined above diligently), it's a perfectly acceptable DIY project. 

Alternatively, if you're still having trouble but don't want to hire a plumber, consider asking a local handyperson for help getting your shower faucet problem fixed. This might be a good way to save a few bucks as well.