Replacing a bathroom faucet is one of the first plumbing projects most homeowners avoid because water is involved and the consequences of getting it wrong are obvious. That caution is worth keeping for complex plumbing work, but a faucet swap is not complex. The water goes off at the shutoff valves under the sink, you replace the unit, and it comes back on. Knowing how to replace a bathroom faucet correctly takes about 90 minutes and requires no special plumbing knowledge.
Before buying a replacement, identify your existing hole configuration. Single-hole faucets need one hole in the sink. Three-hole configurations need holes spaced four inches apart for a centerset faucet or eight inches for a widespread design. Measure the distance between your existing holes before you buy anything.
Reach under the sink and find the two shutoff valves, one for hot and one for cold. Turn them clockwise until they stop. Open the faucet handles to release any remaining pressure and drain the supply lines. Put a towel under the p-trap in case of drips. Disconnect the supply lines from both the faucet and the shutoff valves. If the lines are old and corroded, replace them with new braided stainless lines rather than reconnecting the old ones. They are inexpensive and a corroded line is a leak waiting to happen.
Look underneath the sink for the mounting nuts that hold the faucet in place. These are often in an awkward position and may require a basin wrench, a long-handled tool designed for reaching up into tight spaces under sinks. The HOTO tool kit (see it here) includes a compact version suitable for most bathroom sink configurations. Unscrew the mounting nuts completely and lift the faucet out from above. Clean the sink surface thoroughly where the old faucet sat. Old plumber’s putty or silicone tends to leave a residue that prevents the new faucet from seating correctly.
Most modern faucets include a gasket or rubber base plate that creates a water seal between the faucet and the sink surface. If yours does not, apply a thin ring of plumber’s putty around the base of the faucet before setting it into the hole. Thread the supply lines and mounting hardware down through the hole and hand-tighten the mounting nut from below, then snug it with the basin wrench. Do not overtighten. Tight enough that the faucet does not rotate is enough. Connect the supply lines to the shutoff valves. Hand-tighten first, then snug with a wrench. Most leaks at supply line connections happen from over-tightening that crushes the compression fitting.
Slowly open the shutoff valves one at a time. Watch the connections at both ends of each supply line. Let the water run for two minutes and check every joint. Dry everything before the test so you can identify any new moisture quickly. A slow drip at the compression connection is the most common issue. Usually hand-tightening a quarter turn more resolves it.
This project pairs well with a broader bathroom refresh. If you have recently refinished your bathroom vanity or installed a new exhaust fan, replacing the faucet completes the transformation without requiring a contractor for any part of it. Replacing faucets yourself versus calling a plumber saves a service call fee that often runs one hundred fifty to two hundred fifty dollars. The Family Budget Reset has a section on tracking these DIY savings as part of your annual home maintenance planning. Check the hardwood floor repair guide and the gutter cleaning guide if you are working through home maintenance projects this season. A faucet replacement is the kind of job that builds confidence for slightly larger plumbing work later.
