How to Install a Faucet in a Bathroom Sink

To install a new bathroom sink faucet, you will basically screw together the parts that are provided in the faucet box, using the holes that are already in your sink.

Purchase a faucet with "centers" that match the holes in your sink. Many bathroom sinks have two faucet holes that measure 4 inches from the center of one hole to the center of the other, and the spigot is molded into the one-piece assembly that sits on top of your sink. Buy a faucet with 4-inch centers for this installation.

Turn off the hot and cold water supply lines to the sink. Open the hot and cold faucet valves to drain the water in the faucet into the sink, and to make sure the water supply is completely off. From under the sink, use a basin wrench to loosen the supply line nuts from the bottom of the existing faucet. Remove the faucet. If necessary, use penetrating oil on rusty parts to aid removal. Prepare the sink surface for the new faucet by cleaning the faucet area around the holes on the sink, removing hard water deposits and old plumber's putty or caulk.

Set the new faucet in place, using the gasket seal if one is provided. If there is no gasket, apply plumber's putty to the bottom of the faucet to make a seal. Make sure the faucet is aligned properly on top of the sink. Tighten the new nuts under the sink with the basin wrench until the faucet is secure.

Wrap Teflon tape around the fittings where you will connect the water supply lines. Wrap in the same direction the nuts will turn onto the fittings. Connect the supply lines to the faucet, matching hot and cold. Use an adjustable wrench to tighten the supply line connectors.

Remove the aerator from the spigot. Turn on the water supply, and open the faucet valves. Check for leaks. Replace the aerator.

Things You Will Need

  • Flashlight or work light, optional
  • Basin wrench
  • Penetrating oil, optional
  • Replacement flexible water supply lines, optional
  • Teflon tape
  • Adjustable wrench

Tip

  • If your sink still has old metal supply lines, consider replacing them with new flexible lines. It is a good idea to replace existing flexible water supply lines with new ones when you replace the faucet. If you used plumber's putty, excess putty will squeeze out as you tighten the faucet; simply wipe it away.