How to Replace a Bathroom Faucet

🧰 Tools & Materials

• New bathroom faucet
• Adjustable wrench
• Basin wrench
• Channel-lock pliers
• Bucket or small container
• Towels or rags
• Plumber’s putty or silicone sealant, if required by the faucet manufacturer
• New faucet supply lines, if not included
• Flashlight
• Cleaning supplies

💡 Pro Tip: Before crawling under the sink, place everything you’ll need within reach. Once you’re lying inside the vanity, you won’t want to climb back out every time you need another tool.

Signs It’s Time to Replace Your Bathroom Faucet

A bathroom faucet can last for years, but replacement often makes more sense than repairing an older fixture when:

• The faucet drips even after replacing the cartridge or internal seals
• There is corrosion, pitting, or peeling finish
• Water leaks around the base of the faucet
• One or both handles have become stiff, loose, or difficult to operate
• Water flow has noticeably decreased and cleaning the aerator doesn’t help
• You’re updating the bathroom and want a newer fixture

If the faucet itself works properly but you see water underneath the sink, check the supply lines and drain assembly first. The faucet may not actually be the source of the leak.

Before You Buy

Bathroom faucets aren’t all interchangeable. Before purchasing a replacement, look underneath the sink or measure the existing faucet holes.

Common configurations include:

• Single-hole: One mounting hole for a single-handle faucet
• 4-inch centerset: Three holes with approximately 4 inches between the outer holes
• 8-inch widespread: Separate hot and cold handles with a separate spout, typically spaced 8 inches apart

Your replacement faucet needs to work with the holes already drilled in your sink or countertop.

Also check whether the faucet includes:

• Supply lines
• A new drain assembly
• Mounting hardware
• A deck plate for covering unused holes

💡 Pro Tip: Take a picture underneath the sink before buying your faucet. It gives you a quick reference for the existing connections while you’re standing in the plumbing aisle.

Step 1: Clear Out the Cabinet

Remove everything from underneath the bathroom sink so you have as much working room as possible.

Place a towel across the bottom of the cabinet and keep a small bucket nearby. Even after shutting off the water, the faucet supply lines will still contain some water.

Use a flashlight so you can clearly see the faucet connections behind the sink.

What You Should See: Two water supply lines running from the shut-off valves to the underside of the faucet.

If Yours Looks Different: Some faucets use integrated supply lines that are permanently attached to the faucet. That’s normal—you’ll disconnect them at the shut-off valves instead.

Step 2: Disconnect the Water Supply Lines

With both shut-off valves completely closed, place your bucket or towel underneath the connections.

Use an adjustable wrench to loosen the supply line nuts.

Depending on your setup, you can disconnect the lines from either the faucet or the shut-off valves. If you’re replacing the supply lines anyway, disconnect them completely.

Expect a small amount of water to drain out.

What You Should See: Once disconnected, the faucet should no longer have any water lines attached beneath the sink.

💡 Pro Tip: If your existing supply lines are old, corroded, kinked, or showing signs of wear, replace them while the faucet is already disconnected.

Step 3: Disconnect the Drain Stopper

If your faucet uses a traditional lift rod behind the spout, it will connect to the drain underneath the sink.

Find the horizontal pivot rod coming from the drain pipe. It should connect to the vertical lift rod with a small metal clip.

Remove the clip and disconnect the lift rod.

You usually do not need to remove the entire drain assembly unless your new faucet includes a replacement drain that you plan to install. If you’re replacing it too, see how to replace a bathroom sink drain for the complete process.

What You Should See: The faucet’s lift rod should now be separated from the drain mechanism.

If Yours Looks Different: Many newer faucets use a push-to-close drain and won’t have a lift rod at all.

Step 4: Remove the Faucet Mounting Hardware

Look directly underneath the faucet.

You should see one or more mounting nuts holding the faucet against the sink or countertop.

Use a basin wrench, adjustable wrench, or the installation tool supplied with the faucet to loosen them.

Older mounting hardware can be stubborn, especially if corrosion or mineral buildup is present.

What You Should See: Once the mounting nuts and washers are removed, nothing underneath the sink should be securing the faucet.

💡 Pro Tip: A basin wrench is extremely helpful when the mounting nuts are tucked behind the sink where a normal wrench can’t turn.

Step 5: Remove the Old Faucet

From above the sink, gently lift the faucet straight upward.

If it doesn’t move, check underneath again for mounting hardware you may have missed.

Old plumber’s putty, silicone, or mineral buildup can also cause the faucet to stick. Carefully work the faucet back and forth until the seal breaks.

Avoid aggressively prying against the sink surface.

What You Should See: The faucet should lift away, exposing the mounting holes underneath.

Step 6: Clean the Sink Surface

Remove any old plumber’s putty, silicone, grime, or mineral deposits around the faucet holes.

A plastic scraper can help remove stubborn material without scratching the sink.

Clean and dry the surface thoroughly before installing the new faucet.

What You Should See: A clean, flat mounting surface around each faucet hole.

💡 Pro Tip: Don’t rush this step. Installing the new faucet over old buildup can prevent it from sitting flat and may allow water to work its way underneath the base.

Step 7: Install the New Faucet

Follow the manufacturer’s instructions for your specific faucet.

Install the supplied gasket beneath the faucet base. If the manufacturer specifies plumber’s putty or silicone instead, apply it as directed.

Feed the faucet supply lines and mounting hardware through the appropriate sink holes.

Position the faucet so it sits straight and centered.

Do not fully tighten it yet.

What You Should See: The faucet should sit flat against the sink with the spout centered over the basin.

If Yours Looks Different: Some faucets use a deck plate underneath the faucet while others mount directly to the sink. Use the parts supplied with your faucet rather than trying to reuse the old gasket or mounting hardware.

Step 8: Secure the Faucet From Below

Underneath the sink, install the supplied washers and mounting nuts.

Hold the faucet straight from above while tightening the hardware underneath.

Tighten the mounting nuts until the faucet is secure and no longer moves.

Avoid overtightening.

What You Should See: The faucet should feel solid when you gently move the handles or spout.

💡 Pro Tip: Check the faucet alignment one final time before fully tightening the mounting hardware. It’s much easier to straighten it now than after everything is connected.

Step 9: Connect the Water Supply Lines

Connect the hot and cold supply lines to the appropriate faucet connections.

Typically:

Hot = Left

Cold = Right

Thread each connection by hand first to avoid cross-threading.

Once hand-tight, snug the connection with a wrench. Avoid excessive force.

If your faucet has integrated supply lines, connect them directly to the corresponding shut-off valves.

What You Should See: Both supply lines should run smoothly between the faucet and shut-off valves without sharp bends, twisting, or kinks.

Step 10: Reconnect the Drain Stopper

If your new faucet uses a lift rod, insert it through the opening behind the faucet.

Underneath the sink, reconnect it to the drain’s pivot rod using the supplied strap and clip.

Adjust the connection until the stopper opens fully when the rod is raised and closes completely when pushed down.

What You Should See: The drain stopper should move smoothly between the fully open and fully closed positions.

If Yours Looks Different: If your new faucet includes a push-button drain, follow the manufacturer’s instructions for installing the new drain assembly instead.

Step 11: Turn the Water Back On and Check for Leaks

Make sure the faucet handles are turned off.

Slowly open the cold-water shut-off valve, followed by the hot-water valve.

Watch every connection underneath the sink as the lines pressurize.

Use a dry paper towel around each connection. Even a tiny leak will show up quickly on dry paper.

If everything remains dry, turn on the faucet and allow the water to run.

Check again underneath the sink.

What You Should See: Steady water flow from the faucet with completely dry supply connections underneath.

💡 Pro Tip: Remove the faucet aerator before turning the faucet on for the first time. Run both hot and cold water for about 30–60 seconds to flush debris from the new lines, then reinstall the aerator.

If Something Goes Wrong

The Shut-Off Valve Won’t Completely Stop the Water

Do not disconnect the supply line while water is still flowing.

Try closing the valve gently again, but don’t force an old or corroded valve. If it won’t shut off completely, you may need to shut off the home’s main water supply before continuing.

The Old Faucet Won’t Come Loose

Double-check that every mounting nut has been removed.

If the hardware is corroded, penetrating oil may help loosen it. Mineral buildup or old sealant around the faucet base can also hold the faucet in place.

Work slowly rather than aggressively prying against the sink.

The New Faucet Moves After Tightening

Check that the mounting washer and nut are installed correctly and that the faucet is sitting flat against the sink.

Hold the faucet straight from above while tightening the mounting hardware from below.

A Supply Connection Is Leaking

Turn the water off and inspect the connection.

Make sure the fitting isn’t cross-threaded and that the supply line is properly seated.

Reconnect it and tighten it snugly.

Do not keep tightening harder and harder to stop a leak. Overtightening can damage the fitting or shut-off valve.

The Faucet Has Weak Water Flow

If both hot and cold water have weak flow immediately after installation, remove and inspect the aerator.

Debris disturbed during installation can become trapped inside it.

Flush the faucet with the aerator removed, clean the aerator, and reinstall it.

Hot and Cold Are Reversed

Check the supply connections underneath the sink.

The hot supply should connect to the hot side of the faucet, typically the left, and the cold supply should connect to the right.

🛑 Common Mistakes to Avoid

• Buying a faucet that doesn’t match the sink’s hole configuration
• Forgetting to completely shut off both water supplies
• Reusing old, worn supply lines
• Cross-threading supply line connections
• Overtightening faucet mounting hardware
• Overtightening supply connections
• Using plumber’s putty when the manufacturer specifies a gasket or silicone
• Forgetting to reconnect or adjust the drain stopper
• Turning the water back on without checking underneath for leaks
• Skipping the initial flush before reinstalling the aerator

❓ Frequently Asked Questions

Do I need plumber’s putty when installing a bathroom faucet?

Not always. Many modern faucets include a gasket that seals the faucet to the sink without putty. Follow the faucet manufacturer’s instructions. Some installations may specify silicone instead.

Do I need a basin wrench?

Not necessarily, but it can make removing and installing faucet mounting nuts much easier when space behind the sink is limited.

Should I replace the supply lines with the faucet?

If the existing lines are relatively new and in excellent condition, they may be reusable. If they’re old, corroded, kinked, or worn, this is an ideal time to replace them.

How tight should faucet supply lines be?

Start every connection by hand and then snug it with a wrench. The fitting should be secure without excessive force. Overtightening can damage the connection.

Why is my new bathroom faucet leaking underneath?

The most common causes are a loose or improperly seated supply connection, a leaking drain connection, or water getting underneath the faucet base. Dry everything completely and identify exactly where the first drop appears before tightening anything. If the faucet itself is dripping from the spout or leaking around a handle, see how to fix a leaky bathroom faucet to troubleshoot the internal faucet components.

Can I replace a bathroom faucet without replacing the drain?

Yes. If the existing drain works properly and is compatible with the new faucet, it can often remain in place. However, many new faucets include a matching drain assembly that you may choose to install.

📞 When to Call a Professional

Replacing a bathroom faucet is usually a manageable DIY project, but stop and consider calling a plumber if:

• A shut-off valve won’t close or begins leaking
• The shut-off valve or pipe moves when you loosen the supply line
• You discover heavily corroded plumbing underneath the sink
• A connection continues leaking after being properly reseated
• The sink, countertop, or plumbing needs modification to fit the new faucet
• You discover damaged supply piping inside the wall or cabinet
• You aren’t confident you can restore the plumbing without leaks

A faucet replacement shouldn’t require forcing plumbing connections. If something feels like it’s about to break, stopping early can turn a potentially expensive repair into a simple service call.

Related DIY Guides

• How to Replace a Bathroom Sink Drain
• How to Unclog a Bathroom Sink
• How to Replace a Water Shut-Off Valve
• How to Replace a Kitchen Faucet
• How to Replace a Kitchen Sink