To install a shower mixing valve, remove the faucet handle, cut the pipes, remove the old valve, mount the new valve, and test it. This one-day project requires a wrench, a screwdriver, a pipe cutter, plumbing tape, a torch, flux, solder, couplers, sweat adaptors, a mixing valve and safety gear.
- Remove the faucet handle
Shut off the water supply, unscrew the faucet handle, and remove it.
- Cut the pipes
Uncover the shower access panel, and use a pipe cutter to sever the water pipes 6 inches from the faucet connection.
- Remove the existing valve
Unscrew the old mixing valve from its housing, and pull it out. Put on heavy gloves and eye protection. Place 1/2-inch couplers over the cut pipes, and solder them in place.
- Install the new valve
Wrap plumbing tape around three sweat adaptors, and screw them to the connectors on the new valve. Fasten the adaptors tightly. Screw the valve to the housing frame. Consult the manufacturer's instructions for specific positioning guidelines. Remove the valve cartridge, connect the valve to the water pipes, and solder the pipes together.
- Test the valve
Reinsert the valve cartridge, and reconnect the water supply. Turn on the water, and inspect the pipes for leaks. Close the shower access panel and reattach the faucet handle.