How to Replace a Bathroom Faucet (Step-by-Step)

Replace your bathroom faucet in under an hour with basic tools. Complete guide covering single-hole, widespread, and centerset faucets, plus the pitfalls plumbers see every week.

By Chris Mendenhall

7 min read

Replacing a bathroom faucet sounds like a plumber job. It’s not. With basic tools and the right new faucet, you can swap out a tired or leaking faucet in 45–60 minutes, save $200 on labor, and pick exactly the style you want. This guide walks through how to replace a bathroom faucet for the three common configurations — single-hole, centerset, and widespread — plus how to avoid the small mistakes that turn a one-hour job into a three-hour ordeal.

What You’ll Need

  • Replacement faucet (matching your sink’s hole configuration — see below)
  • Adjustable wrench
  • Channel-lock pliers
  • A basin wrench (~$15 — strongly recommended; reaches the awkward nuts behind the sink)
  • A flashlight or headlamp
  • Plumber’s tape (PTFE / Teflon tape)
  • A bucket and old towels
  • A flathead screwdriver
  • Penetrating oil (for stuck old nuts)
  • Optional: silicone caulk (only if your new faucet doesn’t come with a base gasket)

Step 1: Identify Your Faucet Configuration

Before you buy anything, look at your sink from above. The number and spacing of the holes determines what faucet you can buy. Stand at the sink and count.

  • Single-hole faucet — one hole. The whole faucet is one piece.
  • Centerset faucet — three holes, with the outer two spaced 4 inches apart (center-to-center). The faucet body covers all three.
  • Widespread faucet — three holes, with the outer two spaced 6–16 inches apart. The handles and spout are three separate pieces.
  • Wall-mount faucet — no holes on the sink itself; the faucet comes through the wall behind it.

Stick to the same configuration when replacing. If your sink has three holes 4 inches apart, buy a centerset or single-hole-with-deck-plate. Don’t try to put a widespread in a centerset hole pattern — the math doesn’t work.

Step 2: Turn Off the Water and Clear Under the Sink

  1. Find both shut-off valves under the sink — one for hot, one for cold. They’re usually small chrome or plastic valves at the base of the supply lines.
  2. Turn each clockwise until they stop.
  3. Open the existing faucet to drain remaining pressure and confirm the water is fully off.
  4. Clear everything out from under the sink. You need elbow room.
  5. Put a bucket and an old towel under the work area — there will be drips.

Step 3: Disconnect the Old Faucet

Working under the sink with a flashlight or headlamp:

  1. Disconnect the supply lines from the bottom of the faucet using an adjustable wrench. There’s usually a swivel nut. Disconnect both hot and cold.
  2. Loosen the mounting nuts that hold the faucet to the sink. This is where a basin wrench saves you. These nuts are deep under the sink in a tight space and impossible to reach with a regular wrench.
  3. If the nuts are corroded and won’t budge, spray them with penetrating oil, wait 10 minutes, and try again.
  4. If your faucet has a pop-up drain assembly connected, disconnect the lift rod (a small set screw) and the horizontal pivot rod from the drain pipe.
  5. Once everything is disconnected, the faucet lifts straight up out of the sink. If it’s stuck from years of caulk or hard water, gently work it free.

Step 4: Clean the Sink Deck

Before installing the new faucet, scrub the area around the holes. Years of soap scum, dried caulk, mineral deposits, and gunk will be there. A new faucet on a dirty surface won’t seal well and looks bad. Use a stiff brush and an all-purpose cleaner. Dry the area thoroughly.

Step 5: Install the New Faucet

Read the manufacturer’s instructions for your specific model — they vary slightly. The general flow:

For a single-hole or centerset faucet:

  1. Place the gasket or rubber seal that came with the faucet onto the sink deck.
  2. Drop the faucet through the hole(s) with the supply lines and mounting studs going down.
  3. From below, slide on any washers and thread on the mounting nuts. Hand-tighten first, then snug with a basin wrench. Don’t crank — overtightening cracks ceramic sinks.
  4. Connect the supply lines to the shut-off valves. Wrap a few turns of plumber’s tape clockwise around the threads before threading on the supply line nut. Hand-tighten plus a half turn with a wrench.

For a widespread faucet:

  1. The three components (two handles and a spout) install separately. The spout goes in the center hole, handles in the outer two.
  2. There’s an additional T-connector under the sink that links the two handles to the spout — install it per the diagram in the box.
  3. Otherwise same as centerset: mounting nuts from below, supply lines to shut-offs.

For all types:

Make sure the spout is centered correctly over the sink before fully tightening the mounting nuts. It’s easy to crank everything down and then notice the spout is rotated 10 degrees off.

Step 6: Install the Drain (If New)

Many faucets come with a matching pop-up drain assembly. If yours did, this is the time to install it.

  1. Disconnect the old drain by unscrewing the slip nut on the drain trap and the body of the drain from inside the sink.
  2. Apply a bead of plumber’s putty (or the included rubber gasket) under the lip of the new drain.
  3. Drop the new drain in from above, secure the locknut from below.
  4. Connect the lift rod from the faucet to the pivot rod on the new drain.

If your faucet didn’t include a drain, leave the old drain alone.

Step 7: Turn the Water Back On and Test

  1. Open the new faucet in the fully open position (both hot and cold). This lets air escape as water enters.
  2. Slowly open the shut-off valves — quarter turn at a time. Listen for hissing or watch for drips.
  3. Let water run for 60 seconds at full hot, then full cold, to flush out any debris from the supply lines.
  4. Close the faucet and check every joint under the sink with your hand for moisture. Dry, snug joints = success.

If you have a small drip, snug the leaking joint another quarter turn. Don’t overtighten — strip the threads and you start over.

Common Mistakes to Avoid

Buying the wrong configuration. Measure the hole spacing before you go to the store. Specifically the distance from the center of the outer-left hole to the center of the outer-right hole. 4 inches = centerset, 6–16 inches = widespread.

Skipping the basin wrench. A standard wrench cannot reach the mounting nuts on most under-sink installs. Trying to use pliers will damage the nut and frustrate you for an hour. The basin wrench is $15 and a permanent addition to your tool collection.

Overtightening plastic nuts. Most modern faucet mounting nuts are plastic. They only need to be hand-tight plus a quarter turn. Cranking them will crack them or strip the threads — and you’ll find out the hard way when it leaks weeks later.

Forgetting plumber’s tape. The threaded connection between the supply line and the shut-off valve relies on plumber’s tape to seal. No tape = slow leak that’s hard to spot.

Leaving the old caulk under the new faucet. If you don’t scrape off the old crusty bead of caulk, your new faucet won’t sit flat. It rocks, wobbles, and the seal fails.

Frequently Asked Questions

How long does it take? For a first-timer: 60–90 minutes. Once you’ve done it before: 30 minutes flat.

Do I need to call a plumber if my shut-off valves are stuck? If you turn them and water still flows, yes — you’ll need either replacement valves or to shut off the main water to the house to work on them. A stuck valve is more involved than a faucet swap.

Why do my supply lines look different than the new ones? Supply lines vary in length and connection type. Most new faucets come with built-in supply lines or include adapters. Check before you buy. If you need to replace them entirely, braided stainless steel supply lines are inexpensive and last forever.

How do I match the faucet style to my bathroom? Pick the finish first. Chrome, brushed nickel, and matte black are the three most common. Match it to the existing hardware (drawer pulls, towel bars, light fixtures). Mixing finishes looks like a mistake; matching them looks intentional.

What if my old faucet is American Standard / Moen / Delta / Kohler and my new one isn’t? The actual installation is identical — all brands use the same hole patterns. Brand only matters for warranty and replacement cartridges in the future.

You’re One Wrench Away

Replacing a bathroom faucet is one of those upgrades that feels disproportionately satisfying. The bathroom looks newer immediately. It costs $80–250 for a decent faucet vs. a $300 plumber bill. And the next time something drips, you’ll know exactly what’s behind it because you put it there.

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