Getting Ready to Do the Job

• Before you take on this repair, be sure you have a proper-size Allen wrench and have shut the water lines to the shower. Either close the main line where it comes into the home at the water heater,or remove the panel in the shower wall and close both valves on the water pipes leading to the shower faucet. Many homes do not have access panels, so shutting off the main water is in such a case the only way to stop the water flow to the shower.
  
  

Taking the Handle Off

• On a single-handle shower faucet there is just one handle to remove. This makes the job very easy. Insert the Allen wrench into the screw head at the base of the handle and turn it counterclockwise to take out the screw. This frees the handle from the cartridge stem and allows the handle to slide right off. Pull gently on the handle to remove it.
  
  

Remove the Cartridge

• Under the handle is the cartridge. Remove it by first taking off the component that holds it inside the faucet body. There are several different ways this cartridge might be held in place. A bonnet nut, or a retaining nut, might be screwed on the faucet body, or a clip might fasten the cartridge to the body. Unscrew the bonnet nut with pliers or pull out the clip with pliers, then slide out the faucet cartridge. If the cartridge has screws attaching it to the faucet, unscrew them to remove the cartridge.
  
  

Replacing the Cartridge in the Shower

• The final step is to replace the cartridge with a new one. In some cases, simply washing the cartridge in clean water removes sediments and particles that block the water flow. Try this first if you do not want to buy a cartridge. If the replacement does not stop the leak, try replacing the O-rings around the body of the cartridge. These are round, rubber gaskets that help seal out water.