How to Replace a Bathroom Faucet: DIY Guide & Tips

A persistent drip or a stiff handle can turn the simplest bathroom routine into a daily negotiation. Replacing a bathroom faucet is one of the most rewarding DIY plumbing projects, saving you the cost of a plumber and giving you the satisfaction of a job well done. With the right tools, a few basic steps, and this guide, you can have your new faucet running smoothly in under an hour.

Choosing Your Replacement Faucet

Before you touch a wrench, selecting the correct faucet is the most critical step. You cannot simply buy any faucet; it must match the specific configuration of your sink. Start by measuring the distance between the centers of your existing faucet holes, known as the "center-to-center" measurement. Common configurations include single-hole, widespread (three holes), and centerset (four inches between outer holes). Additionally, consider your plumbing setup; verify whether you have hot and cold water lines entering from the wall or the floor, as this dictates the valve type you need.

Gathering Tools and Shutting Off Water

Success in this project hinges on preparation. You will need an adjustable wrench, a basin wrench (specifically for reaching tight spaces under the sink), channel-lock pliers, a screwdriver set, plumber’s tape, and a bucket. Before any work begins, you must stop the water supply. Locate the shut-off valves, which are usually tucked behind the toilet or under the sink itself, and turn them clockwise to close. If you cannot find dedicated valves, you will need to turn off the main water supply to your home. Open the faucet in the bathtub or sink to drain the remaining water from the lines before proceeding.

Removing the Old Faucet

With the water off and drained, it is time to dismantle the old fixture. Disconnect the water supply lines from the valves using your wrench, being careful to catch any residual water in your bucket. If you cannot access the mounting nuts under the sink due to space constraints, this is where a basin wrench becomes indispensable. Once the supply lines are detached, locate the nuts or screws securing the faucet body to the sink deck. Loosen these mounting nuts and carefully lift the old faucet out of the sink. Take a moment to inspect the condition of the supply lines; if they are cracked or stiff, it is wise to replace them now to prevent a future leak.

Inspecting the Configuration

With the old hardware removed, look down into the sink. You will likely see either a single hole or three distinct holes. If your new faucet is a centerset model and you have three holes, you may need to use the new mounting plate to cover the extra holes. If you have a widespread faucet, ensure the pipes running through the holes are not bent or damaged. This is your last chance to clear any debris left behind before installation begins.

Installing the New Cartridge (For Compression Faucets)

If you are replacing an older two-handle faucet that uses a stem and washer system (a compression faucet), you will likely need to replace the internal cartridge or washers. Hard water mineral buildup often damages these components, causing drips even in new washers. Remove the handle and stem, and inspect the small rubber or nylon washers at the base. If they are cracked or pitted, swap them out for new ones that match the exact size. Taking the old parts to the hardware store ensures a perfect match.

Attaching the New Faucet

Installation is the reverse of removal, but requires care to avoid cross-threading. Begin by threading the supply lines through the holes of the new faucet. Secure the faucet to the sink deck using the provided mounting hardware, tightening the nuts just firmly enough to eliminate wobble without applying excessive force that could crack porcelain. Next, wrap plumber’s tape clockwise around the threads of the supply lines. Screw the lines onto the corresponding valves—remember, hot water is usually left—and tighten them securely with your wrench. Do not overtighten, as this can strip the brass or damage the valve seat.

Testing for Leaks

With the faucet reassembled, slowly restore the water supply by turning the shut-off valves counterclockwise. As the pipes fill, inspect all connections for immediate leaks. Once the water is running, check the faucet handles for smooth operation and verify that the hot and cold flows are correctly labeled. If you notice a leak at the handles, it often means the internal packing nut needs tightening. If the leak is coming from the spout, you may need to reseat the cartridge or tighten the body mount. A little patience during this testing phase saves you from a messy cleanup later.