Fix a Leaky Shower Faucet
By Matt Weber
Don’t blame the showerhead for a leaky spout. The problem originates in the valves behind the shower handles.
When a tub or shower faucet leaks, don’t scowl at the spout. That’s like blaming the messenger for bad news. The trouble lies behind the handles, which turn valves that govern the flow of water to the spout. It’s important to fix these valves as soon as possible because, aside from the irritating drip-drip-drip, a leaky shower faucet can waste a small pond of water every day. The repair is fairly simple, but you’ll need a special set of deep-socket wrenches to get the job done. Don’t fret over the price, though. The wrenches are available at most hardware stores, and Harbor Freight sells a set for only $9.99—compare that to the cost of plumber.
First and foremost, shut off the water supply to the faucet before disassembling the handles.
Modern compression faucets generally have rubber seat washers that seal water from the spout, and the washers can deteriorate over time resulting in a leak. To get to the washers, you must remove the handles which are usually fastened with a threaded retaining nut hidden behind a decorative cap.
Begin by prying off the cap with a screwdriver. (In some cases these caps are threaded.) Then unscrew the nut to pull off the handle.
Next, remove the escutcheon. Escutcheons are often held with a retaining nut, but if not then the escutcheon is threaded over the valve stems. If this is the case, unscrew the entire escutcheon as one piece. If it won’t release, check to see if it’s caulked to the wall, and cut the caulk. A strap wrench may help encourage a stubborn one to turn.
Bath and shower faucets have the valves mounted deeply behind the wall. A box-end wrench won’t usually reach the bonnet nuts that hold them in place, and a standard socket won’t work because the center stem interferes with its reach—thus the need for a special deep socket.
Thread the socket over the stem and secure it tightly over the bonnet nut. Unscrew and remove. Pull the stem from the wall to expose the seat washer and screw. Remove the worn seat washer and replace with a new one, coating it with heat-proof faucet grease. Make sure to use the correct size and shape of seat washer and press it firmly into the stem’s retainer. If the stem is in good shape, you’re ready to reassemble the shower handles and test your faucet.
In some cases, the metal stems may be worn out and require replacement. The valve stems in our project were corroded and pitted around the washer’s retainer, contributing to the leak problem. We replaced both stems entirely, which ran roughly $12.50 each at the hardware store. They slip right into the pipes just like the old ones that we pulled out. (Be sure to use the faucet grease.)
Note: When purchasing the stems, take notice of the stem’s model numbers which are typically labeled with either H or C, indicating hot or cold. These indications determine the direction of handle rotation. You will need one of each and be sure to keep them straight during installation.