Replacing a bathroom faucet costs $150 to $250 when a plumber does it. The same replacement done yourself takes under 2 hours and requires the same hand tools you already own, plus one specialty tool you may need to purchase: a basin wrench. Knowing how to replace a bathroom faucet properly means understanding which tools reach where standard wrenches cannot and checking the sink’s hole configuration before you buy anything.
A new faucet is one of the highest-visual-return bathroom upgrades per dollar, particularly if the existing faucet has tarnished, corroded, or has a finish that no longer matches updated fixtures in the same bathroom.
Check the sink before buying a faucet
Sinks come in three basic hole configurations. A single-hole sink has one hole for a faucet, which works with any single-handle faucet. A three-hole sink with a 4-inch spread has holes with 4 inches center-to-center between the outer holes, which fits most widespread two-handle faucets labeled as centerset or mini-widespread. A three-hole sink with an 8-inch spread takes a widespread faucet with separate valves that mount in the outer holes independently.
Many faucets marketed for three-hole sinks come with a deck plate that bridges the outer holes and covers the gap, allowing a single-handle faucet to install in a three-hole sink with a standard 4-inch spread. Check the product description for deck plate inclusion if your sink has three holes but you prefer the look of a single-handle faucet.
Buying a faucet that does not match the hole count or spread means returning it. Take a quick photo of the underside of your sink showing the holes and bring it when shopping. You can find a wide selection on Amazon with detailed specifications for hole count and spread compatibility.
Turn off the water before anything else
The shut-off valves are the two oval or round handles under the sink, one on the hot water line and one on the cold. Turn each one clockwise until it stops. Then turn on the faucet to release the remaining pressure in the supply lines and let the water drain. Confirm the flow has stopped fully before proceeding. If a shut-off valve does not stop the flow completely, you will need to shut off water at the main house valve and replace the shut-off valve as a separate step before this project.
Disconnect the drain linkage
Most bathroom faucets include a pop-up drain assembly that connects to a lift rod running down through the faucet body. A horizontal pivot rod attached to the drain pipe connects to a vertical lift rod via a clip. Find the pivot rod behind the drain pipe under the sink, squeeze the retaining clip, and slide the pivot rod out. This frees the drain stopper so you can lift it out of the drain. Set the stopper, pivot rod, and clip aside in a bag so they do not get misplaced.
Disconnect and remove the old faucet
Use an adjustable wrench to loosen the supply line connections at the faucet tailpieces. Have a small towel or bucket ready because the lines will hold a small amount of water. Unscrew the connections fully and move the supply lines out of the way.
The mounting nut that holds the faucet to the sink is located under the sink, up against the sink surface, in a space that is too tight for a standard wrench to operate. This is where the basin wrench comes in. A basin wrench has a long telescoping handle and a jaw that swivels, allowing it to reach up behind the drain and grip the mounting nut in a space you cannot see clearly and cannot reach with a standard tool. They are available on Amazon for $15 to $25 and are worth owning for this project and any future kitchen or bathroom faucet work.
The HOTO tool set covers the adjustable wrench and pliers you need for the supply line connections, and adding a basin wrench completes the toolkit for plumbing projects at this level. The guide to the best home tool kit for beginners is worth checking if you are building out your tool collection.
Once the mounting nut is removed, lift the old faucet out from the top. Clean the sink surface of any old plumber’s putty or sealant residue with a plastic scraper and mineral spirits or rubbing alcohol. The new faucet needs to seat on a clean surface.
Install the new faucet
Follow the installation instructions that came with the new faucet. Most modern faucets use a quick-mount system with a single large nut that tightens from below, which is much faster than older faucets that required individual nuts at each hole. Feed the supply lines through the sink hole or holes, set the faucet in position, reach underneath and thread the mounting nut by hand, then tighten firmly with the basin wrench.
Do not overtighten. The goal is snug and stable, not maximum torque. Overtightening a plastic mounting nut cracks it; overtightening against a porcelain sink can crack the sink around the hole. Hand-tight plus a half turn with the wrench is appropriate for most installations.
Reconnect the supply lines to the new faucet tailpieces. Most new faucets include new supply lines in the box. Hand-tighten the connections and add a quarter turn with an adjustable wrench. Do not use thread tape on the supply line connections as they use neoprene washers for sealing, not thread contact.
Reconnect the drain and test
Insert the drain stopper into the drain opening. Feed the new pivot rod through the drain pipe opening and into the stopper’s slot. Clip the pivot rod to the vertical lift rod at a position that gives the stopper full range of motion. Test the lift rod action: pulling up should close the drain, pushing down should open it.
Turn on the shut-off valves slowly, one at a time. Let them open fully and check each supply line connection for drips. Run the faucet for a full minute and watch underneath for any leaks at the supply line connections or around the drain. A drop of water on either connection means hand-tighten another quarter turn and retest.
The skills in this guide directly apply to the guide on how to replace a kitchen faucet, which follows the same process with a slightly larger fixture. The guide on how to fix a leaky faucet covers repairs for faucets that are worth keeping, and how to fix a leaky outdoor faucet extends the same plumbing knowledge to exterior spigots.
Include faucet inspection in your spring home maintenance checklist to catch slow leaks at supply line connections before they become water damage. For a complete home project approach, the Broke Mom Home Reset is a $17 guide that covers which repairs to prioritize and in what order.
