You can replace a bathroom faucet in two to four hours with basic tools

Replacing a faucet is one of the most straightforward plumbing jobs a homeowner can do. You need a wrench, a screwdriver, plumber's tape, and the new faucet itself. The work happens under the sink, where you disconnect the old faucet, remove it, and install the new one in its place. Most people finish in an afternoon without calling a plumber.

The hardest part is usually getting the old faucet loose — corrosion and mineral buildup can make connections stick. If you run into that, penetrating oil and patience solve it. If you damage the supply lines or the sink itself during removal, you may need to replace those too, which adds cost and time.

Key Takeaways

  • Turn off the water supply under the sink before you start, and test that the water is actually off by turning on the faucet.
  • The old faucet connects to two supply lines (hot and cold) and a drain line; you disconnect all three, then unscrew the faucet from the sink deck.
  • New faucets come with mounting hardware and instructions specific to that model, so read them before you start — the order of assembly matters.
  • Plumber's tape wrapped around threaded connections stops leaks; wrap it clockwise around the male threads before you screw anything together.
  • If the shutoff valves under the sink do not work, you will need to shut off the main water supply to the house instead.

Shut off the water and drain the lines

Look under the sink. You will see two small valves on the supply lines coming up from the wall or floor — one for hot water, one for cold. Turn both valves clockwise until they stop. They should turn about three-quarters of a full rotation.

Turn on the faucet at the sink to confirm the water is off. If water still comes out, the shutoff valves are broken or stuck. In that case, go to your main water shutoff — usually in the basement, crawl space, or outside near the foundation — and turn it off there. This stops water to the whole house, so you want to finish quickly.

Leave the faucet on while you work. This keeps air in the lines and makes it easier to disconnect things without water spilling everywhere.

Disconnect the supply lines and drain

Place a bucket or towel under the connections to catch any water still in the lines. Using an adjustable wrench, grip the nut on the hot water supply line (the one on the left) and turn it counterclockwise. The line will unscrew from the faucet. Do the same for the cold water line on the right.

Next, find where the drain line connects to the faucet. This is usually a large nut underneath the sink. Loosen it by hand or with a wrench, then unscrew it the rest of the way. The drain line will come free. Some faucets have a pop-up stopper rod connected to the drain assembly — disconnect that too by unbolting it or sliding it out of its clip.

If the supply lines or drain line are stuck, spray penetrating oil around the nut and wait 15 minutes. Do not force it — you can crack the sink or strip the threads.

Remove the old faucet from the sink

Look at the top of the sink where the faucet sits. Most faucets are held down by two or three bolts underneath the sink deck. Using a wrench or socket, turn these bolts counterclockwise and remove them. The faucet should now lift out from the top.

If the faucet does not budge, it may be sealed with caulk or mineral buildup. Run a utility knife around the base of the faucet to cut any caulk, then try again. Once it comes free, clean the sink deck with a cloth. Remove any old caulk, mineral deposits, or debris so the new faucet sits flat.

Install the new faucet according to its instructions

Every faucet is different. Open the box and read the manufacturer's instructions before you touch anything. The order in which you assemble the faucet matters — some require you to install the base gasket first, others require it last. Some have a single handle, others have two. Some come with a deck plate that covers the old holes.

Generally, you will insert the faucet through the holes in the sink from the top, then tighten the mounting bolts from underneath. Tighten them evenly — a little on one side, then a little on the other — so the faucet sits level. Do not overtighten; you can crack the sink or strip the bolts.

Once the faucet is mounted, reconnect the supply lines. Wrap plumber's tape clockwise around the male threads (the part that screws in) three to four times before you screw the nut on. This creates a watertight seal. Hand-tighten the nuts first, then use a wrench to snug them another quarter turn. Do not crank them — hand-tight plus a quarter turn is enough.

Reconnect the drain and test for leaks

Reconnect the drain line to the faucet, hand-tighten the nut, then snug it with a wrench. If your faucet has a pop-up stopper, reconnect the rod now. Test the stopper by pushing the handle down — the drain should close and open smoothly.

Turn the shutoff valves back on (counterclockwise). Turn on the faucet and let it run for 30 seconds. Check underneath the sink for drips at the supply line connections, the drain connection, and around the base of the faucet. If you see water, turn off the shutoff valves and tighten the leaking connection a quarter turn with a wrench. Turn the water back on and check again.

If the leak is at the base of the faucet where it meets the sink, turn off the water, remove the faucet, and check that the gasket is seated correctly. Reinstall it and test again. Small drips often stop on their own as the gasket settles, but do not ignore them — they will get worse.

Seal the faucet base if needed

If water is pooling around the base of the faucet on top of the sink, you may need to caulk it. Wait 24 hours after installation to make sure there are no leaks, then apply a bead of silicone caulk around the base. Smooth it with a wet finger and let it cure according to the caulk instructions before you use the sink heavily.

Do not caulk if the faucet is still leaking — fix the leak first. Caulk seals the gap between the faucet and sink, but it does not stop water coming from inside the faucet itself.

Frequently Asked Questions

What if the shutoff valves under the sink do not turn?

Spray penetrating oil around the valve stem and wait 15 minutes. Try turning it gently — do not force it or you may break the valve. If it will not budge, you will need to shut off the main water supply to the house instead. After you finish the faucet, consider replacing those shutoff valves so you can isolate the sink next time.

Can I reuse the old supply lines?

You can if they are in good condition — no cracks, kinks, or corrosion. If they are old braided lines or have mineral buildup, replace them. New supply lines are inexpensive and come in standard lengths. Using new lines reduces the chance of leaks.

Do I need plumber's tape on every connection?

Use it on any threaded connection where water flows through — the supply line nuts and the drain nut. Wrap it clockwise around the male threads three to four times. It prevents leaks by filling gaps in the threads. Do not use it on compression fittings or connections that already have rubber washers.

What if water leaks from the faucet handle when I turn it off?

A small drip from the spout for a few seconds after you turn it off is normal — the cartridge or valve inside is settling. If water runs steadily, the faucet may be defective. Check the manufacturer's warranty and contact them for a replacement or repair instructions.

How do I know which supply line is hot and which is cold?

The hot water line is on the left, the cold water line is on the right. This is standard in the United States. The lines may also be labeled or color-coded — red for hot, blue for cold. When you reconnect them, match them to the correct ports on the new faucet, which are also labeled.