Leaks No More: How to Replace a Shower Cartridge in 8 Simple Steps

Shut Off Your Water Supply

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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 your pipes drain. Ask a plumber for help if this task feels out of your wheelhouse.

Shut and Cover Your Bathtub Drain

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It's best to shut your bathtub drain before starting. 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.

Remove Your Shower Handle

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First, you'll need to remove the shower handle to see if the 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 (i.e. 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.

Remove the Escutcheon

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

Remove the 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.

Use the Puller Tool to Remove the Old Shower Cartridge

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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.

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. If you like, you can try removing these and reinstalling them before buying a new kit. A new shower cartridge costs around $50 and may come with a shower cartridge pulling tool.

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.

Retrace the steps you've followed thus far: put the clip back on, 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.

Turn Water Back On, Then Test

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Once everything's back in place, turn the water valve back on and test your work. If there's still a leak, 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 maybe your shower is just 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.