Replacing a shower faucet valve can be divided into two phases: removing the old valve and installing the new valve. There might be many reasons to replace a shower faucet, but a common one is to install a new pressure-balanced valve that senses fluctuations in the system and keeps the water temperature constant, even if other fixtures and appliances are running while someone is showering. This can be an important safety feature to prevent scalding.
Replacing a shower faucet valve is a relatively advanced project that typically requires soldering copper pipes and fittings. However, if you don't have soldering skills—but you do have access to the supply piping—you can install a new valve using CPVC pipe or PEX tubing, neither of which require soldering.
Equipment / Tools
- Allen wrench (as needed)
- Utility knife
- Channel-type pliers
- Mini-hacksaw or tubing cutter
- New shower valve
Remove the Faucet Handle
Start by removing the shower handle. In this example, there is a screw behind the cap that holds the handle in place. In other cases, you may need an Allen wrench to remove the screw and then the handle. Use a rag to cover the shower or tub drain so that screws and small parts don’t fall down the drain.
Remove the Escutcheon Trim Plate
Remove the escutcheon trim place to access the shower valve. With the handle out of the way, you can easily get to the second set of screws that hold the trim plate in place. Unscrew both and then pull the plate off the wall. If there is any caulk around the trim plate, you may need to use a utility knife to cut the bead of caulk before the plate comes off. If there is a protective plate covering the valve, remove it as well.
In this example, the faucet opening in the wall had to be enlarged to remove the protective plate. If you need to do the same, make sure that the hole is only as large as it needs to be in order to minimize wall repair after the new faucet is installed.
Cut an Access Hole
Cut or break open a bigger hole, if necessary, for removing and installing the valves. There are two options: cutting into the wall behind the plumbing cavity or working through a small opening in the surround.
In this example, the hole in the fiberglass shower surround was enlarged from the front side by breaking out pieces with pliers. Other types of wall surfaces might require different techniques for enlarging the faucet opening.
Keep in mind this hole should ideally be hidden behind the cover plate on the new faucet when the project is done. To make sure the hole isn’t too big, use the new cover plate as a guide for gauging how big you can make your hole.
Determine the Where to Cut the Pipes
Determine how to remove the old valve and install the new valve. The shower valve used here has both outside-threaded connections and inside sweat (solder) couplings. Position the new valve in front of the old to determine where the pipes should be cut. Mark the cut locations onto the pipe with a marker.
Every valve may is different, so plan your cuts carefully before you begin. You may need to use other couplings or fittings to route the water pipes into the new valve. Make a list and get all of your materials ready so that the installation goes smoothly.
Remove the Old Valve
Shut the water off and cut the old valve out of the wall, leaving the appropriate amount copper for the new valve. While a copper tubing cutter is generally the best tool for cutting copper pipe, for the tight spaces in a project like this, a mini-hacksaw works well.
Now you are ready to install the new shower valve.