Generally it takes about 7 – 10 years for enough mineral deposits from the water to build up sufficiently to clog the screens and to coat the thermo-coupler so that it is insulated from the water temperature.

In most cases by removing the Thermostatic Cartridge and soaking it in a solution of “CLR”, “LIMEAWAY” or white vinegar will dissolve these minerals and restore the Thermostatic Cartridge to working order.

In extreme cases a new Thermostatic Cartridge can be purchased.


Tools required for removal:

  1. Phillips screwdriver (remove the handle)
  2. Small flat (regular) screwdriver (to close service stops)
  3. Adjustable wrench or 24mm Socket wrench (to remove the Thermostatic Cartridge)
  4. Plumbers grease or “Vaseline” (for O Rings)



  1. Remove Temperature handle. The handles with Red Button, pop off the screw cover in the front center of the handle – this is a round disk with the letters GS stamped in an Oval
  2. Pull off the round white nylon disk
  3. If you can shut off the water to the house it is not necessary to remove the Faceplate. In places where it is not convenient to shut off the water remove the Faceplate and on either side of the Thermostatic Cartridge is a large brass hex shaped nut with a screw in the center. By screwing in these screws (service stops) the water should shut off. Test by turning on shower.
  4. If water is shut off unscrew the Thermostatic Cartridge with either the 24mm Socket Wrench or an adjustable wrench.


The Thermostatic Cartridge should come out in ONE PIECE. The Cartridge is about 4” long and approx. 1 ½” in diameter. If the piece you remove is only about 1 ½” long you have only removed the front stem assembly and the body of the Cartridge is still in the wall.

  1. To remove the body of the Cartridge, should this be necessary, use a ¾” nipple extractor (cam type) see picture attached. If you do not have access to one you can obtain it from us.

6.Soak the Cartridge in CLR, Lime away or vinegar for a few hours until clean.  DO NOT REMOVE THE O RINGS. You risk stretching or breaking them.

  1. Using the corner of a towel or clean rag clean the chamber in the wall that housed the Cartridge.
  2. Remove Cartridge from soaking solution and run under water to rinse. Roll it in a towel to damp dry.
  3. Grease the 3 black O Rings with the plumbers’ grease or other lubricant to prevent snagging and tearing when replacing.
  4. Replace Cartridge and do not over tighten, tighten till firm
  5. You can now turn on the water to the house or open the service stops.
  6. Using the Handle, turn the Cartridge all the way Counter Clockwise. After allowing sufficient time for the Hot water to flow from the water heater the water exiting the showerhead should be the same temperature as the water exiting the water heater. Slowly turn the Handle clockwise until you feel the water is at the temperature you like to shower. Then turn off the shower.

13.Remove the Handle and replace the white nylon disk with the Red line on the edge at the 12 o’clock position. Replace the Handle and tighten the Retaining screw. If the Handle turns stiffly you have over tightened the screw. Slacken it off slightly and the handle should turn smoothly. Replace the screw cover. If you removed the Face Plate you can now replace it.

  1. You should now have Cold water when you turn the Handle clockwise and when you turn the handle counter clockwise it should stop at the preset showering temperature with the Red Button at the 12 o’clock position,

To increase the temperature, press the Red Button to override the safety stop and it will turn to give you maximum temperature. When you turn back to the handle to the position where the Red Button is at the 12 o’clock position (approximately 100 degrees) it will pop back out and lock restrict counter clockwise movement till it is depressed again. This is your anti-scald safety stop.