How to Replace the Cartridge on a Mixet Shower Faucet

By
Aaron Stickley
Aaron Stickley

Aaron Stickley is a licensed plumber with 15 years of experience in commercial, new residential plumbing, and residential service and repair. He started his own residential service and repair plumbing business. Aaron's articles about plumbing on The Spruce span four years.

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Updated on 09/15/22
Reviewed by
Richard Epstein
Richard Epstein
Reviewed by Richard Epstein
Richard Epstein is a licensed master plumber with over 40 years experience in residential and commercial plumbing. He specializes in estimating as well as design and engineering for plumbing systems, and he works for one of New York's largest union plumbing construction companies.
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Fact checked by
Jessica Wrubel
Jessica Wrubel
Fact checked by Jessica Wrubel
Jessica Wrubel has an accomplished background as a writer and copy editor, working for various publications, newspapers and in public libraries assisting with reference, research and special projects. In addition to her journalism experience, she has been educating on health and wellness topics for over 15 years in and outside of the classroom.
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Shower faucet
Prasit photo / Getty Images
Project Overview
  • Working Time: 1 hr
  • Total Time: 2 days, 1 hr
  • Skill Level: Beginner
  • Estimated Cost: $16 to $25

The Mixet company is no longer in business, but thousands of their shower valves are still in operation. When it becomes difficult to divert the temperature from hot to cold on the temperature control, the valve is dripping or takes a lot of tightening to close the valve, the hot and cold water are not balancing properly, or the plastic handle needs repeated adjustment or repairs, it's time to replace the Mixet cartridge.

When repairs are needed, it is a fairly easy and inexpensive job to replace the internal cartridge with one offered by an aftermarket manufacturer, designed to match the original part. Simply look for a replacement cartridge specified to fit the Mixet faucet model you own. 

Before You Begin

Shut off the water to the shower at the nearest branch shutoff (if available) or use the home's main shutoff valve. Turn on a bathroom sink faucet all the way to relieve pressure and drain any remaining water from the pipes.

What You'll Need

Equipment / Tools

  • Screwdrivers
  • Tongue-and-groove pliers
  • Utility knife (as needed)
  • Rag

Materials

  • Replacement cartridge for Mixet faucet
  • Plumber's stem grease
  • Tub and tile caulk

Instructions

  1. Remove the Handle, Temperature Knob, and Escutcheon Plate

    Remove the screw in the center of the handle and then pull the handle straight out and off. Remove the temperature knob by partially unscrewing the screw on the top of the knob. You may need to shake it back and forth and side to side to loosen it for removal. 

    Loosen the setscrew holding the escutcheon plate, then pull the plate off. If the plate is sealed with caulk, cut through the caulk bead with a utility knife to release the plate.

    Mixet Handle
    Aaron Stickley

  2. Remove the Old Cartridge

    Use tongue-and-groove pliers to loosen the mounting nut securing the faucet cartridge. Turn the nut counterclockwise until it comes all the way off. The cartridge will remain inside the valve body after the nut is removed.

    Grip the flat ridges of the cartridge with the pliers, then turn the cartridge side to side while pulling straight out to remove it from the faucet body. 

    Tip

    Some Mixet models have a retaining clip that holds the cartridge in place in addition to the nut. Remove this clip with needle-nose pliers before pulling out the cartridge. 

    Removing a Mixet cartridge
    Aaron Stickley

  3. Install the New Cartridge

    Apply a thin layer of plumber's stem grease to the O-rings on the new cartridge. Align the cartridge for the proper insertion. There is usually a red mark on the cartridge indicating which side is up. If your temperature knob was in the down position, put the cartridge in with the red mark facing up. However, if your temperature knob was in the up position, the red mark should face down.

    Push the cartridge all the way in. If necessary, wiggle it with pliers as you push it in. Make sure the two brass rings are correctly positioned inside the mounting nut, then reattach the nut to the faucet body. Tighten the mounting nut firmly, but periodically check to make sure the cartridge can still be rotated side-to-side. If the cartridge is too stiff you can loosen the nut a bit.

    Installing a new Mixet cartridge
    Aaron Stickley

  4. Reinstall the Plate, Knob, and Handle

    Fit the escutcheon plate back into place (or install a new one if you have it). Install the temperature knob, making sure the little nipple is in the groove of the cartridge before you tighten the screw. Put the handle back in place and secure it with its screw. Turn on the water and test the faucet to make sure it works properly.

    Dry the area thoroughly with a rag. Caulk around the rim of the escutcheon plate to create a watertight seal and prevent water from getting inside the wall cavity. Let the caulk dry for 24 hours before using the shower.

    Installing a Mixet valve handle
    Aaron Stickley

Did You Reverse the Temperature?

It's a common mistake to install a Mixet cartridge so that the temperature controls are reversed—so that the hot is to the right and the cold is to the left. But this is easy to correct. Remove the handle and temperature knobs again, and open the water flow with the handle. While water is flowing through the spout, spin the cartridge in place 180 degrees. Reinstall the temperature knob and handle.

Reverse Mixet temperature control
Aaron Stickley