You can replace a bathroom faucet yourself in two to four hours with basic tools

Replacing a bathroom faucet is one of the most straightforward plumbing jobs a homeowner can tackle. You do not need a plumber's license or special training—just a wrench, a screwdriver, and patience. The work happens under the sink, where you have room to move, and the water shuts off with a straightforward valve turn. Most faucets fail because the internal seals wear out, and swapping in a new one stops the drip and often improves water pressure at the same time.

The actual replacement takes two to four hours the first time you do it. The hardest part is usually removing the old faucet, which may have mineral buildup or corroded bolts. Once that is out, the new one slides in and bolts down in minutes. The job costs between $100 and $300 in materials—the faucet itself, plus new supply lines if yours are old—and saves you $200 to $400 in labor if you had called a plumber.

Key Takeaways

  • Turn off the water supply at the shutoff valves under the sink before you start, and test that the water is off by turning on the faucet.
  • The old faucet bolts down from underneath the sink; you will need a basin wrench or adjustable wrench to reach and loosen them.
  • Measure the distance between the holes in your sink before you buy a new faucet, because they come in 4-inch, 6-inch, and 8-inch spreads.
  • New supply lines (the hoses that connect the faucet to the shutoff valves) cost $10 to $20 and are worth replacing if the old ones are kinked or stained.
  • If the shutoff valves under your sink do not turn or leak, replace them at the same time—they cost $15 to $30 and prevent future water damage.

Shut off the water and drain the lines

Before you touch the faucet, turn off the water supply. Look under the sink and you will see two shutoff valves—one for hot water and one for cold. They are usually oval knobs or small levers on the pipes coming from the wall. Turn both clockwise (or flip both levers down, depending on the type) until they stop. Do not force them; they should turn smoothly.

Once the valves are closed, turn on the faucet at the sink and let the water run until nothing comes out. This drains the lines so water does not spill all over you when you disconnect the supply hoses. If water still drips from the faucet after you have turned the valves off, the shutoff valves are leaking and you should plan to replace them too—they cost $15 to $30 each and take an extra 20 minutes.

Remove the old faucet from underneath the sink

Lie on your back or crouch under the sink with a flashlight. You will see the faucet bolts coming down from the top of the sink. There are usually two or three of them, held tight with nuts on the underside. Use a basin wrench (a specialized wrench with a long handle that reaches up into tight spaces) or an adjustable wrench to loosen these nuts. Turn counterclockwise. If the nuts are stuck, spray them with penetrating oil like WD-40 and wait 15 minutes before trying again.

Once the nuts are loose, you can pull the old faucet up and out from the top of the sink. Now disconnect the two supply hoses—the flexible tubes that carry water to the faucet. They screw onto the shutoff valves with compression fittings. Use an adjustable wrench to hold the valve steady while you turn the fitting counterclockwise with another wrench. Water may drip; have a towel ready. If the hoses are kinked, stained, or more than 10 years old, replace them with new ones (they cost $10 to $20 for a pair).

Clean the sink and measure the hole spacing

With the old faucet out, wipe away any mineral deposits or old caulk from the sink surface where the faucet sat. Use a plastic scraper or old credit card so you do not scratch the finish. This gives the new faucet a clean surface to seal against and prevents leaks.

Before you install the new faucet, measure the distance between the holes in your sink. Faucets come in three standard spreads: 4-inch (center-to-center distance between the outer holes), 6-inch, and 8-inch. If you did not measure before buying, do it now and make sure your new faucet matches. A faucet with the wrong spread will not fit, and you cannot return it once you have opened the box.

Install the new faucet and reconnect the supply lines

Most new faucets come with a rubber gasket or foam seal that goes on the underside of the faucet body. Slide this onto the faucet tailpieces (the tubes sticking down from the faucet) before you push the faucet through the sink holes. Lower the faucet into place from the top of the sink, making sure the spout points the right direction and the handles are where you want them.

From underneath, slide the washers and bolts onto the tailpieces and hand-tighten them first. Once they are snug by hand, use the basin wrench to tighten them another quarter turn. Do not over-tighten; you only need them tight enough that the faucet does not rock. Tighten the bolts evenly—a little on one side, then a little on the other—so the faucet sits flat.

Now reconnect the supply hoses. If you are reusing the old hoses, screw them back onto the shutoff valves by hand first, then use a wrench to tighten them another half turn. If you are installing new hoses, they usually come with compression fittings already attached; just screw them on the same way. Hand-tight plus a half turn is the right amount—over-tightening can crack the fitting.

Turn the water back on and test for leaks

Turn both shutoff valves counterclockwise (or flip the levers up) to restore water pressure. Open the faucet slowly and let the water run for 30 seconds to flush out any debris from the lines. Check the spray pattern and water pressure. If the flow is weak, the aerator (the screen at the tip of the spout) may be clogged; unscrew it, rinse it under running water, and screw it back on.

Now check for leaks. Look under the sink where the supply hoses connect to the shutoff valves and where they connect to the faucet. Wipe the connections dry with a towel, then watch for 10 minutes. A small drip at the connection means the fitting needs another quarter turn with a wrench. If water drips from the faucet body itself or from under the sink where the faucet bolts down, turn off the water, tighten the bolts another quarter turn, and test again. If the leak continues, the gasket may not be seated correctly; you may need to remove the faucet and reseat it.

When to call a plumber instead

If the shutoff valves will not turn or leak when you try to close them, stop and call a plumber. Forcing a stuck valve can break it, and a leaking valve means water is escaping inside the wall. A plumber can replace the valves in 30 to 45 minutes and will catch any other problems at the same time.

If you remove the old faucet and find that the sink is cracked or the holes are stripped (the bolts spin but do not tighten), the sink itself needs repair or replacement. This is beyond a faucet swap and requires a plumber or a sink specialist. Also call a plumber if you discover that the supply lines are soldered copper (not flexible hoses) or if the shutoff valves are not where you expect them—these situations mean your plumbing is older and may need upgrades that are outside the scope of a straightforward replacement.

Frequently Asked Questions

Do I need to turn off the water to the whole house?

No. The shutoff valves under the sink control only that faucet. If those valves do not work, then turn off the main water supply to the house (usually a valve near the water meter or where the main line enters). But in most cases, the local shutoff valves are all you need.

What if the old faucet bolts are stuck and will not budge?

Spray them with penetrating oil (WD-40 or similar) and wait 15 to 30 minutes. Spray again and wait. Try loosening with a wrench, then tighten a quarter turn, then loosen again—this breaks the corrosion seal. If they still will not move after an hour, you may need to cut the bolts with a hacksaw or call a plumber.

Can I install a single-handle faucet if my sink has three holes?

Yes. Single-handle faucets come with a cover plate that hides the unused holes. Make sure the faucet you buy includes this plate, or you can buy one separately for $5 to $10. The faucet still needs to match your hole spacing (4, 6, or 8 inches).

How do I know if my new faucet is the right size?

Measure the distance between the center of the leftmost hole and the center of the rightmost hole in your sink. Faucets are labeled 4-inch, 6-inch, or 8-inch spread. Buy the one that matches your measurement. If you buy wrong, most retailers will exchange it if the box is unopened.

What should I do if water leaks from under the sink after installation?

Turn off the water and check where the supply hoses connect to the shutoff valves and to the faucet. Tighten the fitting another quarter turn with a wrench. If the leak is from under the faucet body at the sink, tighten the mounting bolts underneath another quarter turn. Refill and test. If the leak continues, the gasket may be damaged and you may need to remove and reinstall the faucet.