How to Replace a Shower Valve Cartridge (2024)

Equipment / Tools

Materials

How to Replace a Shower Valve Cartridge

1. Lay a Drop Cloth in the Bottom of the Shower

   Put a drop cloth in the shower or tub to block off the drain. The dropcloth prevents screws, washers, and other small parts from going down the drain and helps keep the area clean.

   

2. Remove the Shower Handle

   The handle or handles need to be removed to access the shower valve. If the shower has a single-lever handle, look for a small set screw in the handle that can be removed with an Allen wrench. Plastic, glass, or faux-crystal decorative handles typically have a small plastic cover over the set screw.

   • Pop off the cover with a flat-head screwdriver to locate the screw. Similarly, two-handle showers will often have screws that are hidden by plastic covers on the front of each handle. Pop off the covers to access the screws.
   • Once the set screws have been found, use a screwdriver or Allen wrench to loosen the screw and pull off the handle.
   • Set the shower handle aside, keeping track of the set screws.
   • Sometimes, the shower valve cartridge can be fully accessed after removing the handle. If this is the case, skip the next step. You do not need to remove the trim plate.

   

3. Unscrew and Clean the Trim Plate

   The trim plate is the flat backing that sits behind the handle. Its purpose is to cover up the shower valve assembly and the hole in the shower wall to prevent water from seeping into the gap between the walls and causing excessive damage to the home.

   • To remove the trim plate, use a screwdriver to loosen the screws securing it to the valve assembly, then slide it off the valve stem.
   • Keep track of the screws, scrape off old caulking, and clean the trim plate and shower handle.
     

   

4. Turn Off the Water

   The water to the shower is controlled with water stops typically located on either side of the shower valve cartridge.

   • Turn off the water using a screwdriver to isolate the shower valve from the rest of the water in the home.
   • If you cannot locate the water stops on the shower valve assembly, turn off the water to the entire home with the main shut-off valve.
   • After turning off the water to the home, turn on a nearby faucet to release the pressure and drain the water line.

   

5. Inspect and Prepare the Area

   Compare the size of the existing hole in the shower wall with the size of the shower valve. In some situations, the shower valve cartridge cannot be removed because the hole in the shower wall is too small to remove the retainer clip or pull out the shower valve cartridge.

   You do not need to expand the hole if the shower valve cartridge, water stops, and the retainer clip can be freely accessed.

   But, if the hole is too small, use a hack saw or an angle grinder to cut the tiles and increase the size of the hole. Keep the hole small enough to fit entirely behind the trim plate.
   

   

6. Remove the Retainer Clip

   The retainer clip is a small piece of metal inserted through the top of the shower valve to secure the cartridge and prevent it from becoming loose or sliding out of position. This clip is easy to remove with a set of needle-nose pliers.

   Grip it with the pliers and pull it up and out of the shower valve. If the retainer clip is in good condition, it can be reused; though most new shower valve cartridges will come with a new retainer clip, reusing the clip isn't ordinarily necessary.

   

7. Pull Out the Shower Valve Cartridge

   • Use standard pliers to grip the shower valve stem and slowly pull the cartridge out of the assembly. Ideally, the cartridge will slide out without a problem.
   • If the cartridge is stuck, use a lubricating solution, like WD-40, or try wiggling it back and forth and up and down to loosen the cartridge.
   • After removing the cartridge, inspect the shower valve assembly to ensure it's in good condition before proceeding.

   Warning

   If there are signs of severe rusting or corrosion, hire a professional plumber to replace the entire shower valve assembly and the surrounding pipes to prevent future problems.

   

8. Install the New Shower Valve Cartridge

   • With the old cartridge out and the shower valve assembly in good condition, the new one should slide in without a problem as long as it's the correct replacement part.
   • Use the new or the old retainer clip to secure the cartridge.

   

9. Turn on the Water and Test for Leaks

   • Test for leaks in the shower valve by turning on the water to the house or simply using the water stops, if applicable.
   • Wipe down the valve assembly with a paper towel to ensure it's completely dry.
   • Wait a few minutes before wiping it again. The absorbent qualities of paper towels make them an excellent leak detector because you will notice as little as one drop of water.

   

10. Reattach the Trim Plate and Shower Handle

    • Slide the trim plate over the stem of the shower valve and secure it with screws.
    • Secure the handle or handles with the set screws.
    • Clean up the drop cloth and any other debris.
    • Test the shower handle to see if it properly controls the flow and temperature of the water.
    • Once everything is working correctly, apply caulk around the trim plate to prevent water from seeping behind the shower wall.