You can replace a sink faucet yourself in one to three hours

Replacing a sink faucet is a task most homeowners can do without calling a plumber, as long as you have basic tools and are comfortable working in a confined space under the sink. The job involves turning off the water supply, disconnecting the old faucet, and installing the new one—no special skills required, though some patience helps. The hardest part is usually removing the old faucet if it has been in place for years, not the installation itself.

The time it takes depends on how corroded the old connections are and how tight the space is under your sink. If everything comes apart easily, you might finish in an hour. If nuts are stuck or your sink cabinet is cramped, budget three hours. Either way, you will save the cost of a service call, which typically runs $150 to $300 before the faucet itself.

Key Takeaways

  • Turn off the water supply at the shutoff valves under the sink before you disconnect anything, and test that the water is off by turning on the faucet.
  • You will need an adjustable wrench, a basin wrench (a specialized tool that costs $10 to $20 and makes the job much easier), and possibly a flashlight and old towels.
  • The old faucet is held on by nuts underneath the sink; loosen these, then pull the faucet up and out from the top, and disconnect the supply lines.
  • New faucets come with instructions specific to that model, so follow those rather than guessing, as mounting hardware varies between brands.
  • If you cannot turn off the water at the shutoff valves under the sink, you will need to shut off the main water supply to the house instead.

What tools and materials you need

Gather these items before you start: an adjustable wrench (one you probably already own), a basin wrench (a specialized wrench designed to reach the nuts under a sink; they cost $10 to $20 at any hardware store and make this job far easier than trying to use a regular wrench in tight quarters), a flashlight or headlamp so you can see under the sink, old towels or a bucket to catch water that drains from the supply lines, and the new faucet with its instruction manual.

Check that your new faucet will fit your sink before you remove the old one. Most faucets are designed for either a single hole (one opening in the sink) or three holes (one for the spout, one for each handle). Some sinks have four or eight holes, and not all faucets work with all configurations. If you are unsure, measure the holes in your sink and compare them to the new faucet's specifications, or take a photo to the store.

How to turn off the water supply

Look under the sink and locate the shutoff valves—these are small knobs or levers on the pipes coming up from the wall or floor, usually one for hot water and one for cold. Turn both clockwise (or flip the lever to the off position if they are lever-style) until they stop. Do not force them; they should turn smoothly.

Once you have turned the valves off, go back to the sink and turn on the faucet to confirm the water is off. If water still comes out, the shutoff valves are not working properly. In that case, you will need to shut off the main water supply to the house instead. This is usually a valve in the basement, crawlspace, or outside near the foundation; turn it clockwise until it stops. If you cannot find it or it will not turn, call a plumber before proceeding.

How to remove the old faucet

Spread old towels under the sink to catch any water still in the supply lines. Look at the underside of the sink and locate the mounting nuts—these hold the faucet to the sink from below. There are usually two or three of them, one for each handle and one for the spout. Use your basin wrench to loosen these nuts by turning them counterclockwise. If you do not have a basin wrench, an adjustable wrench will work, but you will have less room to maneuver.

Once the nuts are loose, go back to the top of the sink and pull the old faucet straight up and out. It may resist if it has been in place for years; wiggle it gently side to side as you pull. Do not yank hard enough to crack the sink. After the faucet is out, disconnect the supply lines—the flexible hoses or rigid pipes that bring water to the faucet. These connect with compression fittings (nuts that screw onto the pipes). Use your adjustable wrench to loosen these nuts and pull the lines free. Expect a small amount of water to spill; that is normal.

Clean the sink surface where the old faucet sat. Mineral deposits and old caulk may be stuck there; scrape these away with a plastic scraper or old credit card so the new faucet sits flat and seals properly.

How to install the new faucet

Read the instruction manual that came with your new faucet before you start. Faucet designs vary, and the manual will tell you the exact order to assemble the parts and where the mounting hardware goes. Some faucets come with a rubber or metal gasket that goes on the underside of the sink; others have the gasket built in. Follow the manual exactly.

Insert the new faucet through the hole or holes in the sink from the top. From underneath, thread the mounting nuts onto the bolts or studs that hang down from the faucet. Tighten these nuts by hand first, then use your basin wrench to snug them down. They should be tight enough that the faucet does not move, but do not over-tighten or you may crack the sink or strip the threads.

Connect the supply lines to the faucet's inlet ports (the connection points where water enters the faucet). These are usually labeled hot and cold, or marked with red and blue tape. Hand-tighten the compression fittings first, then use your adjustable wrench to turn them another quarter turn. They should be snug but not so tight that you cannot loosen them later if you need to.

How to test for leaks and adjust the handles

Turn the shutoff valves back on by turning them counterclockwise (or flipping the lever to the on position). Turn on the faucet and let the water run for a minute to flush out any debris from the supply lines. Check all the connections you just made—under the sink, at the base of the faucet, and where the supply lines connect—for drips or sprays.

If you see a small drip at a compression fitting, try tightening it another quarter turn with your wrench. If it still drips after that, turn the water off, disconnect that fitting, and check that the ferrule (a small metal or plastic ring inside the fitting) is seated properly. Sometimes the ferrule shifts during installation. Reconnect and try again.

Test both hot and cold water, and check that the handles move smoothly and the water shuts off completely. Some new faucets have a slight learning curve for the handle position; if the handle is stiff, a small amount of use will loosen it up. If the water will not shut off completely or comes out in a weak stream, you may have debris in the aerator (the screen at the tip of the spout). Unscrew the aerator, rinse it under running water, and screw it back on.

When to call a plumber instead

If the shutoff valves under your sink do not work and you cannot locate or turn the main water shutoff, stop and call a plumber. Proceeding without being able to turn off the water will flood your home.

If the old faucet is stuck and you cannot remove it after 15 minutes of gentle effort, or if the mounting nuts are so corroded that your wrench cannot grip them, a plumber has specialized tools to remove it without damaging the sink. This is worth paying for rather than cracking the sink yourself.

If you connect everything, turn the water back on, and water sprays or drips from multiple places, or if the water pressure is very low, there may be an issue with the faucet itself or the supply lines. Turn the water off and check that all your connections are tight. If they are and the problem persists, the faucet may be defective, or there may be a problem with your home's water supply that a plumber should diagnose.

Frequently Asked Questions

Do I need to use plumber's tape on the supply line connections?

No. Modern faucet supply lines use compression fittings, which seal with a ferrule (a small ring) rather than tape. Plumber's tape is for threaded connections, which are different. If you use tape on a compression fitting, it can actually prevent a proper seal. Just hand-tighten the fitting, then snug it with a wrench.

What if water leaks from under the sink after I turn the water back on?

Turn the water off when ready and check that all the nuts and fittings are tight. Most leaks are from loose connections. Tighten each one a quarter turn and test again. If the leak is coming from the faucet body itself (not a connection), the faucet may be defective and should be returned.

Can I replace a two-handle faucet with a single-handle faucet?

Only if your sink has a single hole. If your sink has three holes (one for each handle and one for the spout), a single-handle faucet will not cover the extra holes unless you buy a faucet designed for that configuration, or you fill the holes with sink hole covers. Check the new faucet's specifications before you remove the old one.

How tight should the mounting nuts be?

Tight enough that the faucet does not move or rock when you push on it, but not so tight that you are straining with the wrench. If you over-tighten, you can crack the sink or strip the threads on the mounting bolts. A quarter turn past hand-tight is usually right.

What is that aerator at the tip of the faucet, and do I need to install it?

The aerator is a screen that mixes air into the water stream, which saves water and reduces splashing. Most new faucets come with one already installed, but if yours did not, screw it onto the threaded tip of the spout. It is not required to make the faucet work, but it is inexpensive and worth keeping.