How to Replace a Bathroom Faucet

Replacing a bathroom faucet is one of the most satisfying plumbing repairs you can do yourself. A leaking or outdated faucet dragged down the whole bathroom—new fixtures change how a space feels instantly, and the work is straightforward enough that you don't need a plumber's license to handle it. The key is patience at the shutoff valves and understanding how the mounting hardware holds everything together under the sink. Once you've done it once, you'll do it again without hesitation. This guide covers standard single-hole and double-hole faucet installations for typical bathroom sinks. The work happens mostly under the sink, in awkward but manageable quarters. You'll need basic tools, a bucket for water that drains out, and maybe thirty minutes of actual hands-on time. The difference between a botched job and a clean one usually comes down to organizing your workspace and not forcing anything that doesn't want to come apart.

1. Turn off the water supply. Locate the shutoff valves under the sink—there's usually one for hot water and one for cold. Turn both clockwise until they stop. Open the faucet at the sink to release any pressure and confirm the water is off. If the shutoff valves don't work or you can't find them, turn off the main water supply to the house.
2. Disconnect the supply lines. Place a bucket under the connections. Using two adjustable wrenches (one to hold the fitting, one to turn the nut), loosen the nuts where the hot and cold supply lines connect to the old faucet. Turn counterclockwise and unscrew by hand once they're loose. Water will dribble out—that's normal. Set the supply lines aside.
3. Disconnect the drain (if applicable). If your sink has a popup drain connected to the faucet, look for a rod running from the faucet body to the drain assembly. Unclip or unscrew this connection point. You may also need to loosen the large nut (called a coupling nut) that holds the drain tailpiece to the sink opening itself—use a basin wrench if you have one, as it's designed for tight overhead work.
4. Remove the old faucet from above. Go back to the sink and look at the base of the faucet where it sits on the countertop. You'll see mounting nuts underneath (accessed from below) or bolts from above. Use a basin wrench or adjustable wrench to loosen these nuts counterclockwise. Once loose, lift the old faucet straight up and out. If it's stuck, rock it gently side to side. Clean any old caulk or putty from the sink holes with a plastic scraper.
5. Position the new faucet and secure it. Insert the new faucet through the mounting holes in the sink (holes should already be the right size). Drop the mounting washers and nuts down through the underside. Using an adjustable wrench and basin wrench, tighten the nuts evenly and firmly. Don't over-tighten; you want snug, not cranked. The faucet should sit flat and stable on the sink surface.
6. Connect the supply lines. Take the hot and cold supply lines and thread the nuts onto the corresponding ports on the new faucet—hot to hot, cold to cold. Hand-tighten first, then use two wrenches to finish the job: one to hold the fitting, one to turn the nut. Don't over-tighten; these are small connections and easy to strip. Tighten until snug, then a quarter-turn more.
7. Reconnect the drain (if needed). If you disconnected a popup drain, reattach the rod to the faucet body using the same clip or screw you removed earlier. Make sure the rod is positioned so the popup closes and opens smoothly. Tighten the coupling nut that holds the drain tailpiece back to the sink opening. Test the drain—it should close fully and open when you pull the handle.
8. Turn on the water and check for leaks. Slowly turn both shutoff valves counterclockwise to restore water. Open the faucet handle and let water run for 10–15 seconds to push air out of the lines. Close it, then inspect all three connection points (hot line, cold line, and drain) for drips or leaks. Check every 5 minutes for the next 15 minutes. If you see dripping at a nut, tighten it slightly with a wrench—do not over-tighten.