How to Replace a Kitchen Faucet

Replacing a kitchen faucet is one of the most satisfying plumbing upgrades you can do yourself. A new faucet transforms how your sink feels—better spray, cleaner lines, fewer leaks—and the work itself is straightforward enough that you don't need a plumber's license to get it right. The key is taking your time underneath the sink where things are tight and wet, and knowing that the job is almost always simpler than it looks from above. What separates a clean installation from a frustrating one is preparation: knowing exactly what's under there before you start, having the right new faucet for your setup, and not forcing anything when old connections resist.

1. Locate and close water supply. Look under the sink and locate the shut-off valves on both the hot and cold water lines. They're usually oval knobs or lever handles attached to the copper or plastic pipes coming up from the floor or wall. Turn each valve clockwise (or flip the lever perpendicular to the pipe) until they stop. Open the faucet above to confirm the water is off. If you can't find shut-off valves under the sink or they won't turn, you'll need to find and close the main water valve for the house.
2. Disconnect hot and cold lines. Place a bucket or towel under the connections where the supply lines meet the old faucet. Using two adjustable wrenches—one holding the fitting and one turning the nut—loosen the connection nuts on both the hot and cold lines. Turn them by hand once they're loose enough. Water will still drip from the lines even after shutoff, so let it drain into the bucket. Fully unscrew and remove both supply lines.
3. Unbolt the old faucet. From underneath the sink, locate the mounting bolts or nuts that secure the faucet to the counter or sink deck. These are usually on threaded studs that come down from the faucet base. Using an adjustable wrench or socket wrench, turn the nuts counterclockwise to loosen them. If they're stuck, apply a penetrating oil and wait 10 minutes. Once loose, unscrew them by hand and set them aside. The old faucet should now lift away from the deck. Some faucets also have a center ring that screws down on the deck—unscrew that too if present.
4. Scrape and dry the deck. With the old faucet removed, you'll see the holes and residue left behind. Scrape away old caulk or plumber's putty using a plastic scraper or old credit card—don't gouge the surface. Wipe the area clean with a damp cloth and let it dry completely. If the new faucet has different hole requirements than the old one, you may need to drill new holes or fill old ones with matching caulk; check the new faucet's specifications before proceeding.
5. Mount the new faucet. Unpack the new faucet and lay out all components. Most modern faucets come with a rubber gasket or stainless steel ring that goes on the underside of the deck where the faucet sits. Slide the gasket onto the faucet's threaded studs, then position the faucet over the correct holes in the deck. From underneath, thread the mounting bolts or nuts onto the studs. Hand-tighten them first, then use a wrench to gradually tighten them in an alternating pattern—snug, don't force. The faucet should sit flush and level on the deck.
6. Connect water supply lines. Connect the new hot and cold supply lines to the corresponding lines coming from the wall or floor. These connections are usually made with compression fittings or threaded connections that screw together. Align the hot line (usually marked red) to the hot supply and the cold line (usually marked blue) to the cold supply. Hand-tighten the connection nuts first, then use two wrenches—one to hold the fitting, one to turn the nut—to tighten until snug. Don't over-tighten; you're sealing a rubber washer, not torquing a bolt.
7. Attach spray head hose. If your new faucet has a pull-out or pull-down spray head, the hose will be threaded through the faucet body. Locate where the hose connects at the base—usually a threaded female fitting. Screw the hose connection onto this fitting and tighten by hand, then use a wrench to snug it further. Make sure the hose doesn't kink or wrap around any drain pipes or shut-off valves.
8. Reopen valves and inspect. Turn both shut-off valves under the sink back on—open them fully by turning them counterclockwise or flipping levers parallel to the pipes. Turn on the faucet at full hot and full cold and let water run for 30 seconds to flush air from the lines. Check every connection point—under the deck at the supply line fittings, at the faucet base, and along any hoses. Wipe connections with a dry cloth first so you can spot leaks immediately. Small weeping indicates a loose connection; turn off water and tighten slightly with a wrench.
9. Install aerator, test flow. Most new faucets come with an aerator—a small screen that screws into the tip of the spout. Screw it in by hand until snug, but don't over-tighten or you'll damage the threads. Turn on the faucet and check that water sprays evenly without sputtering. If the flow seems weak or uneven, the aerator may need cleaning; unscrew it and rinse it under hot water, then replace it.
10. Seal the base with caulk. If there's a gap between the faucet base and the counter deck, apply a bead of silicone caulk around the perimeter. Use a caulk gun and run an even line around all sides. Wet your finger with water and smooth the caulk into a concave seal. This keeps water from running under the faucet and damaging the counter or the cabinet below. Let the caulk cure per the manufacturer's instructions—usually 24 hours—before heavy use.
11. Test spray and handle function. Pull the spray head down or out depending on your model and test that it pulls smoothly and that water switches from the main spout to the spray without hesitation. Let go and confirm the head snaps back into place and locks in the up position. Rotate the handle through its full range of motion and confirm hot and cold water are correctly positioned. Adjust the lever or cartridge orientation if needed per the manual.