How to Install a New Kitchen Sink Faucet

Installing a new kitchen faucet is one of the most satisfying plumbing jobs you can do yourself—the payoff is immediate and visible every time you use your sink. A worn-out or leaking faucet gets replaced the same way regardless of style: you're essentially unplugging the old one and plugging in the new one. The hardest part isn't the skill; it's working in the cramped space under your sink without losing a bolt into the abyss. Once you've done it once, you'll realize how straightforward the work is. Most faucets come with installation instructions, but those diagrams are often cryptic. This guide walks you through the actual sequence so you know what to expect when you're lying on your back staring up at copper pipes.

1. Stop the Water Flow. Locate the shut-off valves under the sink—there should be two, one for hot and one for cold water. Turn both valves clockwise until they stop. Turn on the faucet at the sink to confirm the water is off. If the valves don't shut off completely or are stuck, you'll need to shut off water at the main.
2. Free the Supply Lines. Place a bucket under the shut-off valves to catch residual water. Using an adjustable wrench, loosen the compression fitting where the supply line connects to the shut-off valve—turn counterclockwise. You may need to hold the valve body steady with a second wrench so it doesn't spin. Once loose enough, hand-tighten to unscrew completely. Repeat for both hot and cold lines. If the lines are stuck or corroded, soak the fitting with penetrating oil for 10 minutes first.
3. Strip the Visible Hardware. Look at the top of the sink where the faucet meets the counter or rim. If there's a decorative plate or gasket collar, you'll need to remove it. Some faucets have a collar that unscrews by hand; others have a metal clip underneath. Check the old faucet's manual or look underneath at the mounting hardware. You may need a basin wrench (a specialized tool with a long handle that fits into tight spaces) or a regular wrench depending on the design.
4. Release the Underside Bolts. The faucet body is held in place by bolts or a mounting bracket underneath the sink. Using your basin wrench or adjustable wrench, loosen these nuts by turning counterclockwise. You may have two nuts (for a center-mount faucet) or more (for a widespread faucet with separate handles). Loosen all of them before trying to remove any, so the faucet comes free evenly. Once loose, you can usually unscrew them by hand.
5. Extract the Old Unit. Once all mounting hardware is disconnected, pull the faucet up and out through the sink opening. You may need to wiggle it slightly or angle it to clear the supply line connections. If it's stuck due to old caulk or mineral deposits, use a putty knife to gently break the seal around the base. Once removed, clean the sink opening of any old putty, caulk, or debris with a cloth or plastic scraper.
6. Clean the Mounting Surface. With the old faucet out, inspect the sink deck or countertop where it sat. Scrape away any old putty, silicone caulk, or mineral buildup with a plastic scraper or old credit card. Wipe the area completely dry with a clean cloth. For most new faucets, you'll install a rubber gasket or foam seal that comes with the new unit—this eliminates the need for caulking, though some installers prefer a thin bead of silicone for extra security.
7. Position the Gasket Layer. Check your new faucet's manual for the exact sequence—most units come with a rubber or foam gasket that goes under the faucet base, and some have a plastic positioning bracket or escutcheon. Slip the gasket over the faucet body (or place it on the sink opening, depending on the design). If your faucet has a center-mount configuration, align the spout and handle with the sink's hole. For widespread faucets, the handles and spout go into separate holes—consult the manual for exact spacing.
8. Seat the Faucet Body. Guide the faucet body up through the sink hole (or holes, if it's a widespread model). Make sure the supply line stubs clear the hole and don't kink. For center-mount faucets, push straight up and ensure the base sits flush on the gasket. For widespread models, start with the center spout, then position each handle in its hole. Everything should sit level—if it rocks or tilts, pull it out and reposition the gasket.
9. Secure the Mounting Bolts. Reach underneath and locate the mounting bracket or bolts that came with your new faucet. These are usually plastic or metal and slide over the faucet's supply line stubs. Tighten the bolts hand-tight first, then use your basin wrench or adjustable wrench to snug them. Don't over-tighten—ceramic valves inside the faucet can crack if you crush the mounting bracket. Snug is enough; you're not installing an engine.
10. Reconnect Water Supply. Your new faucet should come with stainless-steel braided or plastic supply lines pre-attached or included in the box. Slide the compression nut (the threaded end) onto the new supply line's end, then screw it onto your existing shut-off valve. Hand-tighten first, then use your wrench to snug it another quarter-turn. Connect both hot and cold lines. If the lines are too short or too long, you can buy adjustable length lines at the hardware store, but most standard faucets accommodate typical cabinet depths.
11. Verify No Leaks. Slowly turn both shut-off valves counterclockwise to reopen the water supply. Turn the faucet handle to hot and cold and let water run for 30 seconds to purge air from the lines. Check underneath the sink for drips or leaks at all connection points. Look at the mounting bolts and supply line fittings. If you see drips, tighten the offending fitting a quarter-turn with your wrench and retest. Minor weeping at a compression fitting usually stops once you've run water for a minute.
12. Seal for Extra Protection. If your faucet has a wide base and you want an extra seal against water creeping underneath, apply a thin bead of silicone caulk around the perimeter where the faucet base meets the sink or counter. Use a caulking gun and a smooth, wet finger to shape the bead. This is purely cosmetic and protective—the gasket does the real sealing. Allow the caulk to cure per the product instructions (typically 24 hours) before putting the cabinet back in service.