How to Fix a Leaky Faucet

Most leaky faucets need either a new washer, O-ring, or cartridge replacement, which takes 30 minutes and basic tools.

1. Stop the Water Flow First. Locate the shut-off valves under the sink and turn them clockwise until tight. If you can't find them or they don't work, shut off the main water supply to your house. Turn on the faucet to drain any remaining water from the lines.
2. Pop Off the Handle. Look for a screw on top of or behind the handle. Remove this screw with a screwdriver, then pull the handle straight up or wiggle it gently while pulling. Some handles have a decorative cap that pops off to reveal the screw underneath.
3. Know Your Faucet Style. Look at what's exposed after removing the handle. Compression faucets have a packing nut around a stem. Ball faucets have a rounded cap. Cartridge faucets have a cylindrical cartridge. Ceramic disk faucets have a wide cylinder with slots on top.
4. Swap the Washer Out. Unscrew the packing nut with pliers or a wrench. Pull out the stem assembly. At the bottom, you'll find a rubber washer held by a brass screw. Replace both the washer and screw with exact matches from the hardware store. Also replace the O-ring around the stem if it looks cracked or hardened.
5. Replace Seats and Springs. Remove the cap and collar with pliers. Lift out the cam, packing, and ball. Replace the seats and springs in the bottom of the faucet body using needle-nose pliers. Replace the ball if it's corroded. Reassemble with new O-rings and packing.
6. Extract and Replace Cartridge. Remove any retaining clips or nuts holding the cartridge in place. Pull the cartridge straight out with pliers, noting its orientation. Replace it with an identical cartridge, making sure it goes in the same way. Replace any O-rings while you're at it.
7. Clean and Reseal Cylinder. Remove the cylinder cap and lift out the disk cylinder. Clean the inlet and outlet ports with a plastic scouring pad. Replace the seals on the bottom of the cylinder if they're cracked or warped. If the cylinder itself is cracked, replace the entire unit.
8. Restore Water, Check Works. Put everything back together in reverse order, making sure all connections are snug but not overtightened. Turn the water supply back on slowly and test the faucet. If it still leaks, you may need to tighten connections or double-check that replacement parts are properly seated.