How Do I Change The Temperature Control Cartridge For My Three Handle Tub / Shower Faucet?

This article will explain how to install a temperature control cartridge for a 3-handle pressure-balanced shower faucet.

Please note that the images are for reference only. The product shown in this article may differ from yours, but the information below is still relevant.

To install the cartridge, you must:

1. Remove the cartridge as well as the seat and spring.
2. Install the new cartridge, seat, and spring.
3. Test for leaks.

Please Note: Before doing any work on your faucet, please shut off the water supply for the faucet.
Once the water is turned off, you are ready to begin.

Step 1 – Remove the old cartridge, the seat, and the spring.

• Remove the handle.
• The threaded shank of the cartridge assembly is held to the valve by a trim ring/lock nut.  This piece has flat sides to accommodate a wrench.  Twist counter-clockwise to remove.  

• With the trim ring/lock nut removed, pull the threaded shank of the cartridge assembly straight out. Remove the cartridge by holding the stem and pulling it straight out.

• Locate the seats and springs and then remove them. If you cannot remove the seat and spring with your fingers, use a pair of needle-nose pliers or a straightened paper clip to remove them.

Step 2 – Install the new cartridge, seat, and spring.

• Install the new seats and springs. To do so, insert the spring into the faucet body. The larger end of the spring goes in first. Next, install the rubber seat over the spring.

• To install the new cartridge stem, note the metal plate at the back has a crescent-moon-shaped opening.  Insert the cartridge stem into the valve so the apex of this curve is the top center of the valve.
   

• To install the new threaded shank of the cartridge assembly, note the small brass notch that sticks out of the side at the base.  This fits into a matching groove in the valve body at the top center.
   
• Reinstall the trim cap/lock nut threaded shank with an adjustable wrench twisting clockwise.  This piece requires 10-14 lbs of torque.  Generally, it is hand-tight, plus a half-turn clockwise.  Fit the extender set into the end of the threaded shank.

Step 3 – Test for leaks

• Once all of the parts are re-installed, turn on the water supply for the faucet and let the water run for approximately 10 minutes. If you notice that water is leaking from the ceramic disc cartridge, tighten the lock nut and test again.