You can replace a bathroom sink faucet yourself in one to three hours with basic tools

Replacing a faucet is one of the most straightforward plumbing projects a homeowner can tackle. You will need an adjustable wrench, a screwdriver, a bucket or towel to catch water, and possibly a basin wrench (a specialized tool that costs $10 to $20 and makes the job easier). The process involves turning off the water supply, disconnecting the old faucet, and connecting the new one—no soldering or special skills required. Most people finish in an afternoon, though your first time may take longer.

The hardest part is usually working in the tight space under the sink, not the plumbing itself. If you run into a stuck bolt or a fitting you cannot loosen by hand, you stop and call a plumber rather than risk cracking the sink or the faucet. This is a good project to learn on because the consequences of a mistake are low: you can turn the water back on, dry everything out, and try again or call for help.

Key Takeaways

  • Turn off the water supply at the shutoff valves under the sink before you disconnect anything, and test that the water is actually off by turning on the faucet.
  • Use a basin wrench to reach the bolts that hold the faucet to the sink from underneath—it is the only tool that fits in that space reliably.
  • Disconnect the supply lines (the flexible hoses that bring water to the faucet) by loosening the nuts where they attach, and have a bucket ready to catch residual water.
  • Install the new faucet by reversing the process: feed the supply lines through the sink hole, tighten the mounting bolts from underneath, and reconnect the supply lines to the new faucet.
  • Turn the water back on slowly and check for leaks at every connection before you consider the job done.

Turn off the water and test that it is actually off

Look under your sink. You will see two shutoff valves—one for hot water and one for cold—attached to the pipes coming up from the wall or floor. They usually have a small handle or knob. Turn both handles clockwise until they stop. Do not force them; they should turn smoothly.

Now go back to the sink and turn on the faucet. Water should not come out, or it should come out very slowly and then stop. If water still flows normally, the shutoff valves are not working. In that case, you need to shut off the main water supply to the house (usually a valve near the water meter or where the main line enters the house) before you proceed. Do not skip this step—working on a faucet with the water on will flood your cabinet.

Once the water is off, turn the faucet handle to the "on" position and leave it there. This relieves pressure in the lines and makes disconnection easier.

Disconnect the old faucet from underneath the sink

Place a bucket or towel under the supply lines. These are the flexible hoses (usually braided metal or rubber) that connect the shutoff valves to the faucet. Loosen the nut where each supply line attaches to the faucet using an adjustable wrench. Turn counterclockwise. Water will drip out—that is normal. Disconnect both lines and set them aside.

Next, locate the bolts that hold the faucet to the sink. They are underneath the sink, attached to the faucet body. You will need a basin wrench to reach them. A basin wrench has a long handle and a small head that pivots, designed specifically to fit into the tight space under a sink. Slide it up behind the faucet, position the head over the bolt, and turn counterclockwise. Loosen both bolts until the faucet is loose enough to lift out from the top.

From above the sink, pull the old faucet straight up and out. You may need to wiggle it gently. Once it is out, wipe away any old caulk or putty around the sink hole with a damp cloth.

Install the new faucet and reconnect the supply lines

Check the new faucet's instruction sheet. Most faucets come with a rubber gasket or a mounting plate that goes on top of the sink, under the faucet body. Install this first if your faucet requires it. Then feed the faucet's supply line tails (the short tubes coming down from the faucet) through the sink hole from the top.

From underneath, slide the mounting bolts through the holes in the faucet body and hand-tighten them. Use the basin wrench to tighten them fully, turning clockwise. Do not over-tighten—you want them snug, not stripped. The faucet should sit flat and stable on the sink.

Now reconnect the supply lines. The hot supply line (usually marked red or with a red tag) connects to the hot water shutoff valve. The cold supply line (usually marked blue or with a blue tag) connects to the cold water shutoff valve. Hand-tighten the nuts first, then use the adjustable wrench to snug them another quarter turn. They should be tight enough that they do not leak, but not so tight that you strip the fitting.

Turn the water back on and check for leaks

Turn both shutoff valves counterclockwise slowly. Let the water run through the faucet for 10 to 15 seconds to flush out any debris from the lines. Then turn the faucet off and watch underneath the sink for drips.

Check three places: where the supply lines connect to the shutoff valves, where they connect to the faucet, and where the faucet body meets the sink. If you see a drip, tighten that connection a quarter turn with the wrench and check again. Small drips often stop once the connection has seated for a few minutes.

If a connection continues to drip after you have tightened it, turn the water off, disconnect that line, and inspect the nut and the fitting for damage. Sometimes the rubber washer inside the nut is cracked or missing. If the fitting itself is damaged, you will need a new supply line. If the washer is the problem, you can replace it—they cost a dollar or two at any hardware store.

Common problems and when to call a plumber

The most common issue is a shutoff valve that will not turn or that leaks after you turn it off. If a valve is stuck, do not force it—you can break it and then you will have no way to stop the water without shutting off the main supply. Call a plumber to replace the valve.

Another frequent problem is a bolt that is corroded or stuck and will not loosen. If you cannot turn it with a basin wrench after a few tries, stop. Forcing it risks cracking the sink or stripping the bolt. A plumber has tools and experience to remove stuck bolts without damage.

If you turn the water back on and water sprays out from under the sink or the faucet does not work at all, turn the water off when ready and check your connections. Make sure both supply lines are hand-tight and that the faucet's inlet holes are not blocked. If everything looks connected correctly and water still will not flow, the faucet itself may be defective—contact the manufacturer or the retailer where you bought it.

Choosing the right faucet for your sink

Bathroom sink faucets come in three main styles: single-handle, double-handle, and widespread. A single-handle faucet has one lever that controls both hot and cold water. A double-handle faucet has separate handles for hot and cold. A widespread faucet has handles spaced far apart, usually 8 inches or more, and requires three holes in the sink.

Before you buy a new faucet, count the holes in your sink. If you have one hole, you need a single-handle faucet. If you have two holes close together, you need a double-handle faucet. If you have three holes or holes spaced 8 inches apart, you can use a widespread faucet. If your new faucet has fewer holes than your sink, you can cover the extra holes with decorative caps that come with the faucet or are sold separately.

Check the faucet's reach—the distance from the back of the faucet to the tip of the spout. If your sink is deep or you have a large counter, you want a faucet with enough reach that water lands in the basin, not on the counter. Most faucets list this measurement in the product description.

Frequently Asked Questions

Do I need a basin wrench?

A basin wrench makes the job much easier because it is the only tool that fits in the tight space under most sinks. You can sometimes use an adjustable wrench or a socket wrench if you have a lot of clearance, but a basin wrench costs $10 to $20 and is worth having. If you do not want to buy one, most hardware stores rent them for a few dollars.

What if water keeps dripping after I tighten the connection?

Turn the water off and disconnect that supply line. Look inside the nut for a small rubber washer—it may be cracked, hardened, or missing. Replace it with a new one (they cost less than a dollar) and reconnect. If the washer looks fine, the fitting itself may be damaged and the supply line may need to be replaced.

Can I replace a faucet if I have old galvanized pipes instead of modern copper or PEX?

Yes, as long as the shutoff valves work and the supply lines are in good condition. If the shutoff valves are stuck or leaking, or if the supply lines are cracked or corroded, have a plumber replace them before you install the new faucet. Trying to force old valves or lines can cause bigger problems.

How long does it take to replace a faucet?

Most people finish in one to three hours. Your first time may take longer because you are learning the steps and working in an unfamiliar space. If you run into a stuck bolt or a valve that will not turn, stop and call a plumber rather than risk damage.

Do I need to use plumber's putty or caulk around the new faucet?

Check your faucet's instructions. Some faucets come with a rubber gasket that seals the gap, and you do not need putty. Others require a bead of plumber's putty or silicone caulk around the base. If your faucet requires it, explore a thin bead around the base after you have tightened the mounting bolts from underneath.