A leaky shower unit is annoying and wastes money. Fixing a leaking shower head requires either replacing the shower cartridge or cleaning the shower head. If the leak is at the head, most often a new washer and some cleaning resolves the leak. A leak around the handle or from the shower head with the water off requires replacing the shower diverter cartridge.
Turn off the water supply to the shower. The access panel for the shower shut-off valves are in the adjacent room of the shower wall. If you cannot locate the shut off valves, turn off the main water supply to the home.
Pry off the cover from the top of the faucet handle with a flathead screwdriver. Turn the screw in the centre of the handle counterclockwise with a Phillips-head screwdriver. Pull the handle away from the wall.
Locate the clip securing the shower cartridge to the wall plumbing. The clip is a C-clip and is near the wall cover plate. Remove the clip with a small flathead screwdriver or a pair of needle-nose pliers. Grab the end of the cartridge with the pliers, and pull the cartridge out of the wall plumbing. Take the cartridge to a home improvement centre for a replacement. Purchase a cartridge that is the same length and diameter as the current cartridge.
Insert the new cartridge into the wall plumbing, pushing the cartridge in as far as it will go. Insert the clip into the cartridge to lock the cartridge to the house plumbing. Jiggle the cartridge as necessary to fully insert the clip.
Slide the handle over the cartridge stem until the handle sits flush to the cover plate. Secure with the retaining screws, and push the cap onto the handle.
Lay a cloth over the connecting nut securing the shower head to the arm. Turn the connecting nut counterclockwise with an adjustable wrench, while holding the arm steady with one hand. Holding the shower arm prevents the arm from turning when removing the shower head connection.
Pull the shower head off the shower arm, and remove the rubber washer just inside the neck of the shower head. Replace the washer with a new one if the washer has damage.
Place the nozzle end of the shower head in a solution of 50 per cent vinegar and 50 per cent water. Let the shower head soak for 30 minutes. Clean out each nozzle opening with a toothpick, and rinse in cold water.
Set the new washer inside the neck of the shower head. Ensure that the washer sits flat inside the shower head without any twists or bends.
Wrap the shower arm threads with new plumber's tape. Thread the shower head onto the arm until tight. Turn the shower head connection another 3/4 turn with the adjustable wrench.