How to Change a Bathroom Faucet

The leaking faucet handle in the master bathroom once read “cold” but now just cries “old.” This vestige of the 1980s, in all its cut-plastic glory, is not quite the period detail you had in mind when you bought the place. What you need is a serious faucet, made of brass and steel and finished in gleaming chrome, elegant nickel, or strapping dark iron. Turn its weighty handles and the tap shuts with such finality you feel like you’re sealing off the hatch of a ship.

The good news is that you’re only a few wrench cranks away from the spigot of your dreams. Most new faucets come as an ensemble with all the components you need, including matching spout, handles, drain collar, and sink stopper. So, as This Old House technical editor Mark Powers demonstrates here, your faucet-assembly time will be held to a couple of hours. Then all you’ll be able to think when you look at your upgraded sink will be: “Wow, that’s hot!”

Steps

Bath Faucet Overview

Before you can install a bathroom faucet, you need to know what type to buy. The majority of faucets for bath sinks have three parts: a center spout and two valves (on which the handles fit). Water passes through separate hot and cold supply lines controlled by the valves, then mixes in a tee and comes out the spout. Most standard sinks have three holes to accommodate these parts. However, the distance between the holes determines what type of faucet you can fit onto the sink.

After you remove the old faucet, measure from center to center on the two outer holes. If that distance is 6 inches or more, you will be able to install a wide-spread faucet (like the one in this project), which requires manually connecting the two valves to the mixing tee. But if there are only 4 inches between the holes, you need to get a center-spread or a mini-wide-spread faucet, a single unit encompassing the valves, the spout, and the connection between. A center-spread faucet has an escutcheon plate linking the pieces on top of the sink, while a mini-wide-spread looks like three independent pieces when viewed from above.

Faucets usually come from the manufacturer with everything except the lines to connect the water supplies to the valves (some handles are sold separately). For these you can use braided lines, which are very easy to install but should only be used where hidden; or rigid lines, which work better when the area under the sink is exposed.

Putting the faucet on is just a matter of piecing everything together in the right order. But TOH plumbing and heating expert Richard Trethewey says that novices can get tripped up in making connections, either by overtightening fittings (which can crack the sink or cause leaks) or by not holding lines steady as they turn the wrench. “If you’re not careful, you can twist the line and impede water flow,” he says. You should also be careful not to twist yourself as you work beneath the sink.

Install the Spout

Turn off the hot- and cold-water shutoff valves under the sink. Remove the faucet and supply lines. Unscrew the metal rim around the drain (the drain collar) from the pipe underneath (the drain rim). Clean all the holes with rubbing alcohol.

To begin installing the new faucet, center the spout in the sink’s middle hole. From below, slide the flat washer over the threads, then screw on the mounting nut.

Hand-tighten the nut and three-way spout tee

Hand-tighten the nut. Then have a helper hold the spout centered on the top of the sink, making sure the hole for the drain stopper’s lift rod faces the back. Using a basin wrench, snug the mounting nut until the spout is secure.

Hand-tighten the three-way spout tee at the spout’s bottom (as shown), leaving the openings facing the hot and cold valves. Check the spout’s alignment, then lock into place by tightening the set screw on the back with an Allen wrench.

Tip: Don’t over tighten the mounting nut or you could risk cracking the sink porcelain.

Install the Hot and Cold Valves

Loosen the mounting nut and washer on one of the valves, then push the valve up through the sink hole. Attach the escutcheon from above. Tighten the mounting nut (from under the sink) by hand, then with a wrench. Repeat for the other valve.

Fit the Faucet Handles

Screw the two short braided lines to the hot and cold valves and then to each side of the spout tee. Finger tighten all four nuts. Then, using an adjustable wrench, tighten each one another quarter-turn. Don’t overtighten these nuts because you could damage the compression fittings and cause leaks.

Fit the faucet handles onto the valves. Adjust them so they face straight to the sides when turned off and straight forward when on. Hold these positions by tightening the set screws with an Allen wrench.

Tip: If the braided line is too long, make a loop in it so it doesn’t kink.

Fit the Rigid Supply Lines

(If you’re using braided supply lines, skip to Step 10.)

If your faucet valves are not directly above your water supply lines, you’ll need to bend the top portion of the rigid supply lines into an S shape so they will reach the valves and screw onto them straight.

Slide a tube bender over the supply line and bring it to the end with the acorn head. Being careful not to kink the metal, gingerly bend the line. Make a second bend in the other direction to get the pipe to gracefully zigzag; the ends should be offset from each other but still look parallel.

Mark and Cut the Rigid Supply Line

Slide a ½-inch nut from a compression fitting onto the line and screw it loosely to the faucet valve over the acorn head. Hold the bottom of the line next to the water shutoff valve, and mark it ¼ inch below the edge of the valve’s threaded shank. Disconnect the line and use a pipe cutter to cut along this mark. Repeat on the other supply line.

Hook up the Supply Lines

For braided supply lines: Screw the ½-inch compression fitting to the faucet valve. Screw the ⅜-inch fitting to the water shutoff valve.

For rigid supply lines: Slide a ½-inch nut from a compression fitting onto the supply line (you don’t need the brass ring, or ferrule, here). Hand-tighten it to the faucet valve over the acorn head. Slide the ⅜-inch nut and then a ferrule from the fitting onto the line. Hand-tighten the nut to the water shutoff valve over the ferrule.

Using an adjustable wrench tighten the ½-inch nut an extra quarter-turn. Then, using tongue-and-groove pliers, hold this connection steady while you tighten the ⅜-inch nut on the water shutoff valve a quarter-turn. Repeat for the other supply line.

Tip: Get more access to the connection at the water shutoff valve by removing the valve’s knob. Just be sure to hold the knob to keep the water supply turned off as you loosen its set screw.

Install the Drain Collar

Using tongue-and-groove pliers, unscrew the nuts holding together the trap, the drain tailpiece, and the drain rim under the sink, and remove them all. Thread a large mounting nut, fiber washer, and rubber washer onto the new drain rim.

Apply clear silicone to the underside of the new drain collar. Slide the drain rim up into the drain hole from beneath. Screw the drain collar onto the rim, making sure the hole in the drain rim faces the back. Then tighten the mounting nut to the sink from underneath. Wipe away any excess silicone that oozes out from under the drain collar.

Wrap the threads of the old drain tailpiece with Teflon tape. Attach it to the drain rim. Reassemble the trap.

Connect the Pop-up Waste Assembly

The drain stopper and the rod that opens and closes it are part of the pop-up waste assembly. The lift rod is screwed to a metal strap with holes that hold a horizontal ball rod. The other end of the ball rod catches the bottom of the stopper. The ball fits into a hole in the drain rim and is held there by a metal nut. The stopper moves via this ball joint whenever the lift rod moves.

To assemble the pieces, slide a plastic washer, then the metal nut from the drain rim, then one side of a spring clip onto the long end of the ball rod. Stick the end of the rod through one of the holes on the strap and secure it with the spring clip. Put another washer on the short end of the ball rod and slide it into the drain rim. Hold the stopper in the drain and catch its hook with the rod. Test that the stopper opens high enough to let water out. If not, use a different hole in the strap or adjust the stopper’s hook by unscrewing it.

Secure the Rods

To secure the ball rod, screw the metal nut onto the drain tailpiece, but leave it loose enough for the ball to move smoothly. With the stopper open, thread the lift rod down through the back of the spout and the top of the strap. Tighten the set screw on the strap to hold the lift rod.

Turn on the water supply, and check for leaks. Unscrew the aerator on the spout, turn on the faucet to flush out the system, then put the aerator back.

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