You can replace a bathroom faucet in two to four hours with basic tools
Replacing a bathroom faucet is one of the most straightforward plumbing projects a homeowner can tackle. You do not need a plumber's license or special training — just a wrench, a screwdriver, and the ability to follow steps in order. The hardest part is usually getting the old faucet out, not putting the new one in.
The job breaks into three phases: shutting off the water, removing the old faucet, and installing the new one. Most of the time you spend will be under the sink, where corrosion and tight spaces slow you down. Plan for two to four hours your first time; experienced homeowners often finish in ninety minutes.
Before you start, buy your new faucet and read its installation manual. Faucets vary — some come with the drain stopper mechanism built in, others do not; some need a special wrench, others do not. Knowing what you are working with before you begin saves frustration later.
Key Takeaways
- Shut off the water at the shutoff valves under the sink first, then turn on the faucet to release pressure before you disconnect anything.
- The old faucet is held down by nuts under the sink; use an adjustable wrench or basin wrench to loosen them, then pull the faucet up and out from the top.
- Clean the sink surface where the old faucet sat before you install the new one, because old caulk and mineral deposits will prevent a watertight seal.
- New faucets usually come with a rubber gasket or putty that seals the base; follow the manual for which one your faucet uses, because using the wrong one causes leaks.
- Test for leaks under the sink before you close the cabinet, because catching a problem now takes five minutes instead of five hours later.
Turn off the water and release the pressure
Look under the sink. You should see two shutoff valves — one for hot water, one for cold — where the supply lines enter the faucet. Turn both valves clockwise until they stop. Do not force them; they should turn smoothly. If they do not turn at all, they are likely frozen from years of sitting unused, and you may need to call a plumber to replace them before you can safely work on the faucet.
Once both valves are closed, turn on the faucet at the sink and let the water run until it stops. This releases the pressure in the lines so water does not spray when you disconnect them. Leave the faucet in the on position while you work.
Disconnect the supply lines and drain
Place a bucket or towel under the supply lines. Use an adjustable wrench to loosen the nuts where the hot and cold lines connect to the faucet. Turn them by hand once they are loose enough to grip. Water will drip — that is normal. Disconnect both lines and set them aside.
Next, look at the drain. Most bathroom sinks have a pop-up stopper connected to a rod that runs under the sink. You will see a horizontal rod attached to the faucet body or the drain assembly. Unscrew or unclip this rod from the stopper mechanism. You do not need to remove the entire drain assembly unless your new faucet requires it — check the manual first.
Remove the old faucet from underneath
The faucet is held to the sink by nuts on the underside. You will see two or three large nuts where the faucet posts come through the sink. A basin wrench is the right tool for this job because it reaches into tight spaces; an adjustable wrench works if you do not have one, but it is slower and more frustrating.
Loosen each nut by turning it counterclockwise. Once they are loose enough, you can often finish by hand. Remove all the nuts and set them aside — you will not use them again. Now go to the top of the sink and pull the old faucet up and out. It may resist if caulk sealed it; use a putty knife to gently break the seal, then pull again.
Once the faucet is out, you will see the holes where it sat. Scrape away all the old caulk, putty, and mineral deposits with a putty knife or old credit card. Wipe the area clean with a damp cloth and let it dry completely. A clean surface is the only way to get a watertight seal with the new faucet.
Install the new faucet and reconnect the lines
Read your new faucet's manual to see whether it uses a rubber gasket, plumber's putty, or silicone caulk to seal the base. Some faucets come with a gasket already attached; others require you to apply putty around the base before you insert the faucet. Do exactly what the manual says — using the wrong sealant is the most common reason new faucets leak.
Insert the faucet posts through the sink holes from the top. Underneath, hand-tighten the nuts onto the posts. Once they are snug, use your wrench to tighten them another quarter turn. Do not over-tighten — you only need them tight enough to hold the faucet in place and compress the gasket or putty. Over-tightening can crack the sink or strip the threads.
Reconnect the hot and cold supply lines to the faucet. Hand-tighten first, then use the wrench to snug them. Again, quarter-turn past hand-tight is enough. If you reconnect the drain stopper rod, align it so the stopper moves smoothly up and down without binding.
Turn the water back on and check for leaks
Turn both shutoff valves counterclockwise to restore water pressure. Turn on the faucet and let it run for a minute. Check underneath the sink for any drips or sprays at the supply line connections, at the base of the faucet, or at the drain. Small drips at the supply connections sometimes stop after a few minutes as the rubber washers settle; if water is still dripping after five minutes, turn off the water and tighten that connection another quarter turn.
If water is leaking from the base of the faucet where it meets the sink, the seal is not watertight. This usually means the surface was not clean enough, the wrong sealant was used, or the faucet was not tightened evenly. You will need to remove the faucet, clean the surface again, and reinstall it with the correct sealant.
Once you confirm there are no leaks, you are done. Close the cabinet and use the faucet normally. It is common for the faucet to feel slightly loose or to move a tiny bit when you first use it — this settles down after a day or two of normal use.
Common problems and how to fix them
The old faucet will not budge. Corrosion can freeze the nuts in place. Spray them with penetrating oil (like WD-40) and wait fifteen minutes, then try again. If they still will not turn, you may need to cut the supply lines with a hacksaw and replace the shutoff valves as well — this is when calling a plumber makes sense.
Water sprays from the supply line connections. The rubber washers inside the nuts are worn out. Turn off the water, disconnect the line, and unscrew the nut. You will see a small rubber washer inside; replace it with a new one from the hardware store (they cost less than a dollar). Reconnect and test.
The new faucet leaks from the base. The seal failed. Turn off the water, remove the faucet, clean the sink surface thoroughly with a cloth and rubbing alcohol, let it dry completely, and reinstall with fresh sealant. This time, tighten the nuts evenly — alternate between left and right as you tighten, like tightening a car wheel.
The faucet handle is hard to turn or stuck. Do not force it. This usually means debris got into the valve when you turned the water back on. Turn off the water, remove the handle (usually a set screw holds it), and rinse the valve stem under clean running water. Reinstall and test.
Frequently Asked Questions
Do I need a special wrench to remove the old faucet?
A basin wrench makes the job much easier because it reaches into the tight space under the sink, but an adjustable wrench works if you are patient. A basin wrench costs about ten dollars and is worth having if you plan to do this more than once.
What if there are no shutoff valves under my sink?
You will need to shut off the main water supply to the house. The shutoff is usually in the basement, crawlspace, or outside near the foundation. Turn it clockwise until it stops. After you finish the faucet, turn it back on. Consider having a plumber install shutoff valves under the sink so you do not have to do this again.
Can I use the old faucet's supply lines with the new faucet?
Only if they are the same length and connection type. Most new faucets come with new supply lines, and using the old ones can cause leaks or compatibility problems. Use what comes with the faucet unless the manual says otherwise.
How long does plumber's putty need to dry before I turn the water on?
Check your faucet's manual — most putties are ready immediately, but some need thirty minutes to an hour. Silicone caulk usually needs longer, sometimes overnight. Turning the water on before the sealant is ready is how leaks start.
What if the new faucet does not fit the existing holes in my sink?
Most faucets fit standard four-inch or eight-inch hole spacing, but older sinks sometimes have different spacing. Measure the distance between the holes before you buy the faucet. If the new faucet does not match, you will need to drill new holes or have a plumber do it, which adds cost and complexity.