When you have to replace the shower mixing valve will be a bit tougher than just replacing a faucet because this part of the shower is behind the wall. If you have a tiled wall this will require you to remove the tile from the wall and then replace it once you are finished.
If you are adding a bathroom or remodeling remember to add a access panel this will prevent you from having to remove and replace your tile, if you don’t have a access panel then unfortunately you will have to create one by breaking through the wall.
Here are the steps you will need to take to make:
- Always remember to turn off the water. If you have traditional plumbing, you will need to shut the water to the whole house. Turning it off just to the shower might not work depending on where your shower mixing valve is located.
- Remove the shower faucet handle and pry the escutcheon plate from the wall. If your new valve includes a showerhead, use adjustable pliers to remove the old shower arm; you will need to turn it counterclockwise.
- At this point, you will need to get into the access panel to gain access to the shower valve. If you have a closet or bedroom wall adjoining the shower you might be able to locate the panel on that wall; if you don’t have a panel but do have the wall adjoining the shower you can save your tile but cut into the wall and create a panel.
- Cut the pipes attached to the old valve making the cuts 6 inches from where it is attached to the faucet. If the pipes come up from the floor, bend 90 degrees and connect horizontally to the valve, cut 6 inches below the elbows. Remember to cut the pipe leading to the showerhead.
- Remove the hardware that holds the old valve in place. Prepare the pipes for the new valve by soldering a 1/2-inch copper coupler onto each of the pipes. Prepare the new valve by attaching the brass sweat adapter to each water port and the outlet for the showerhead. Don’t forget to wrap plumbing tape around each adapter before you attach it, tighten with a wrench.
- Replace the hardware to secure the valve making sure to leave enough space from the front wall for the trim. Your instruction manual will have the proper distance. Once secure, test to make sure the trim fits. to avoid damaging the cartridge remove it from the valve when soldering the connections.
- Cut another 1/2-inch copper pipe, and attach it to the proper fittings that will connect the valve to the installed couplings. Before you solder it all together make sure you dry-fit everything to verify it fits, spread your flux on each joint and solder it with lead-free solder.
- After you have completed this install the cartridge, after checking all the connections turn on the water and look for leaks. Now that you verified there are no leaks close the wall up and install the shower escutcheon, handle, and showerhead.
Make sure you check with your local building department you might need a permit, check local codes to verify if your new valve needs to balance water pressure and limit temperature to prevent scalding. With all that down now you can sit back and relax at a job well done!