Stop that Leak! Replacing Bath & Shower Valves
Updated: Apr 2
Do the leaks in this photo look familiar?
When a tub or shower faucet leaks, the trouble often lies behind the handles, which turn the valves that control the water flow. These valves should be fixed quickly; aside from the irritating dripping sound, a leaky faucet can waste a lot of water on a daily basis. Repairs are fairly simple, but you’ll need a special set of deep-socket wrenches called a “shower-valve socket wrench set.”
A shower-valve set provides the super-deep wrenches needed to remove tub and shower valves. The wrenches are each double-sided, accommodating the 10 standard sizes of plumbing fasteners to make most any residential shower or bath valve repair. The wrench sets are available at most hardware stores for about $15.
Shut off the water supply to the faucet before disassembling the handles.
Modern faucet valves usually have rubber washers that seal water. Over time, the washers can deteriorate and leak. To get to these, first pry the decorative cap off the
handles. (In some cases these caps are threaded.)
Remove the handle’s retaining nut and pull the handle off the valve stem.
Remove the escutcheon, which is often held with a retaining nut. If not, then the escutcheon is threaded over the valve stems, and you can unscrew the entire escutcheon as one piece. Cut away any caulk that might be holding it to the wall. A strap wrench may help encourage a stubborn one to turn.
The bonnet nut that holds the valve stem in place is recessed behind the wall, requiring a special wrench. A deep-socket shower valve wrench will fit over the protruding valve stem and reach the bonnet nut for removal. Unscrew and remove the bonnet nut.
Pull the stem from the wall to expose the black, rubber seat washer and retaining screw. Remove the screw and worn seat washer. Replace with a new washer, coated in heat-proof faucet grease. Use the correctly sized and shaped seat washer and press it firmly into the stem’s retainer. If the metal valve stem is in good shape, you’re ready to reassemble the shower handles and test your faucet. Sometimes all that's needed is a new rubber washer.
However, some metal stems may be corroded, worn out, and need replacement. When purchasing the new stems, note the model numbers, typically labeled with either H or C, indicating hot or cold. These determine the direction of handle rotation. Get one of each; be sure to keep them straight during installation. The valves are sold in different sizes per manufacturer, so it's a good idea to take the old valves to the hardware store to ensure an exact match.
Coat the rubber seat washer with heat-proof faucet grease and install the new valve stem. Note: If the threaded junction of the shower head and plumbing spout leaks, wrap the threads with thread-seal tape in the same direction that the head screws onto the spout, then reinstall the shower head.
Editor’s Note: The images in this article are excerpted from The Quick & Easy Home DIY Manual by Matt Weber published by Weldon Owen.