How to Replace a Faucet

Swapping out a tired, drippy faucet is one of the most satisfying weekend upgrades you can make — and it’s well within reach for a first-timer. Do it right and you get a leak-free fixture that looks brand new; skip a step and you can wind up with a slow drip inside the cabinet that quietly rots your vanity and floor for months before you notice.

What you’ll need

• New faucet — match your sink’s hole count (1, 3, or 4 holes) before you buy; brands like Moen, Delta, and Kohler cover most kitchens and baths
• Basin wrench — the one tool that makes reaching the mounting nuts behind the sink actually possible
• Adjustable wrench — for the supply-line coupling nuts
• Channel-lock pliers — for stubborn drain and supply connections
• Braided supply lines — always replace the old ones; buy two sized to fit your new valves
• Shut-off (angle stop) valves — only if your existing ones are corroded or won’t fully close
• Plumber’s thread-seal tape or pipe dope — for any threaded metal connections
• Silicone caulk or plumber’s putty — to seal the faucet base against the deck
• Cleaner and rag — the old base leaves grime you’ll want gone before setting the new faucet
• Work light or headlamp — the cabinet is dark; a good light is not optional
• Gloves and a small bucket or towel to catch drips

Step 1: Shut off the water and drain the lines

Reach under the sink and turn both shut-off valves clockwise until they stop — one for hot, one for cold. If there are no under-sink valves, or they won’t close, shut off the main water supply to the house instead. Then open the old faucet (both handles) to release pressure and let the remaining water drain out. Keep a towel and small bucket handy.

Common mistake: old angle-stop valves can seize or start weeping the moment you turn them. If a valve won’t fully close or drips after you touch it, plan to replace it while you’re in there — grab new shut-off valves. If it’s soldered copper rather than a compression fitting, that’s a job for a plumber.

Step 2: Disconnect the supply lines

Put a bucket under the connections. Use an adjustable wrench to loosen the coupling nuts where the supply lines meet the shut-off valves, then the ones at the faucet tailpieces. A little water will spill — that’s normal. Once both lines are free, set them aside. You’ll be installing fresh braided supply lines rather than reusing the old ones, which stiffen and crack with age.

Step 3: Remove the old faucet

The faucet is held down by mounting nuts threaded onto the tailpieces up inside the cabinet. This is where a basin wrench earns its keep — its swiveling jaw grabs nuts you can’t see or reach with a normal wrench. Loosen and remove the nuts, disconnect any sprayer hose, then lift the faucet up and out from the top. If it’s stuck to the deck by old putty or caulk, work a putty knife under the base to break the seal.

Scrape and wipe the sink deck completely clean with a rag and cleaner. A smooth, clean surface is what lets the new faucet seat flat and seal properly.

Step 4: Set the new faucet

Most modern faucets come with a rubber or foam gasket that seals the base — if yours does, you usually don’t need putty. If it doesn’t, run a bead of silicone or roll a rope of plumber’s putty under the base plate. Feed the faucet’s tailpieces and supply tubes down through the sink holes, position it straight, and press it into place. From below, thread on the mounting nuts and snug them by hand, then tighten with the basin wrench. Check from above that the faucet is centered and square before you fully tighten.

Pro tip: don’t overtighten. Plastic mounting nuts crack and thin sink decks can flex or crack if you crank on them. Firm and snug is the goal, not maximum torque.

Step 5: Connect the water lines

Attach your new braided supply lines from the faucet tailpieces down to the shut-off valves — hot to hot, cold to cold. Hand-tighten the coupling nuts, then give them about a quarter to half turn more with a wrench. Braided lines with rubber-gasketed ends generally don’t need tape. For any threaded metal connection, wrap the threads with a few turns of thread-seal tape first. Don’t reconnect the drain or sprayer with the wrench so tight you strip it.

Step 6: Turn the water on and check for leaks

Remove the faucet aerator if the instructions say to (it clears debris on first run), then slowly open both shut-off valves. Turn the faucet on and let it run hot and cold for a minute. Now get your work light and inspect every connection under the sink — run a dry finger or paper towel around each nut. Any moisture means snug that fitting a touch more. Reinstall the aerator once the water runs clear.

Don’t skip this: check again after 10 minutes and once more the next day. A connection that looks dry at first can develop a slow weep under steady pressure — catching it now saves your cabinet floor later.

Frequently asked questions

That’s the whole job — a fixture that looks new and a cabinet that stays dry. If you hit a corroded valve or need a specific part today, your local independent hardware store can hand you the right fitting and a second opinion on the spot. Stuck on which faucet fits your sink? Ask us here and we’ll point you the right way.