How to Install a Pressure-Balance Shower Valve

In this video, This Old House plumbing and heating expert Richard Trethewey renders shower water temperatures safe.

Steps:

1. Turn off the water leading to the bathroom. Then use pliers and a manual handle puller to remove the faucet handles and escutcheons from the hot- and cold-water faucets.
2. Unthread the faucet stems from the shower wall using an adjustable wrench.
3. Using a level, mark level and plumb lines onto the shower wall, indicating the horizontal and vertical centers of the existing shower valve.
4. Take the paper template that came with the new shower valve and hold it against the shower wall.
5. Align the template with the centerlines marked in Step 3, then trace the outline of the template onto the shower wall.
6. Use a drill/driver and 3/16-inch-diameter masonry bit to drill a series of closely spaced holes through the tiled wall. Be sure to drill the holes just inside the template outline.
7. Next, connect the holes by cutting through the tile using a hammer and ½-inch-wide cold chisel.
8. After chiseling through the tile, pull away the tiled wall section to expose the old shower valve. Use a drywall saw to trim away any ragged edges of drywall.
9. Use pliers to carefully twist off the tub spout. If there’s a setscrew beneath the spout, loosen it first before trying to remove the spout.
10. Remove the access panel from the rear of the shower wall. Then, use a reciprocating saw fitted with a metal-cutting blade to cut through the pipe connecting the old valve to the showerhead.
11. Using pliers, loosen the threaded unions that secure the shower valve to the water-supply pipes. Then, remove and discard the old valve.
12. Cut short lengths of copper pipe to join the new shower valve to the existing water-supply pipes, tub faucet and shower riser.
13. Brush flux onto the pipes and fittings, then solder the new valve into place.
14. With the new pressure-balance valve installed, move around to the tub side and screw on the finished escutcheon plate.
15. Wrap Teflon tape around the tub-spout stub-out, then thread on the new tub spout; tighten the spout by hand, don’t use pliers.
16. Screw the handle onto the center of the new shower valve.
17. Snap the index onto the handle to conceal the screw head.

Tools