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How to fix a leaky faucet
A faucet dripping once per second wastes roughly 3,000 gallons a year, and the cause is almost always a worn seal inside the faucet: a cartridge, a washer, or an O-ring. The repair is beginner-level, but the part depends on your faucet type, so diagnosis here means identifying what you own before you buy anything.
Take the old part to the store with you. Faucet parts look nearly identical across brands and differ by millimeters, and the removed part is the only reliable shopping list.
Tools required
- Adjustable wrench and Allen key set
- Flathead and Phillips screwdrivers
- Needle-nose pliers
- Penetrating oil, for stuck handles
- Towel and painter tape, to protect the finish
Materials required
- Replacement cartridge or washer kit matched to your faucet
- O-rings, assorted pack
- Plumber's grease
- White vinegar, for mineral cleaning
Step by step
Identify the faucet type
One handle that lifts and turns is a cartridge faucet, disc or ball depending on brand. Two handles usually mean cartridges or, on older faucets, compression washers. A drip from the spout points to the cartridge or washer. A leak around the handle or base points to O-rings.
Shut off the water
Close the supply valves under the sink and open the faucet to drain pressure. No valves under the sink? Use the main shutoff and open a lower faucet too. Plug the drain so a dropped screw does not become a second project.
Remove the handle and trim
Pry off the decorative cap, remove the screw, and lift the handle, using penetrating oil and patience on a stuck one. Photograph the assembly as it comes apart. The order of small parts is the reassembly instructions.
Pull the cartridge or stem
Note any retaining clip or nut, then pull the cartridge straight out with pliers on its stem, rocking gently. On compression faucets, unscrew the stem assembly and find the washer at its end, held by a small screw. Replace exactly what you find, in the orientation you found it.
Clean, grease, replace
Soak mineral-crusted parts in vinegar and wipe the valve body clean. Fit new O-rings with a dab of plumber's grease, seat the new cartridge aligned as the old one sat, and reassemble in reverse photo order.
Test slowly
Turn the water back on with the faucet open, let air clear, then close and watch for a full minute. Check under the sink too. A drip that persists usually means the cartridge is not fully seated or the valve body itself is scored.
Finishing and upkeep
Keep the old cartridge and the new one's packaging in a labeled bag under the sink. The next drip, years from now, becomes a ten-minute fix with the part number already in your hand.
When to call a pro instead
Call a plumber if there are no shutoff valves and the main is your only option on a tight schedule, if the valve body inside the wall leaks, or if the faucet is a wall-mounted or specialty unit. Body failures inside walls are not washer problems.
Questions homeowners ask
Why does it still drip after a new washer?
The brass seat the washer presses against can be pitted or scored, so the new washer cannot seal. Seats are replaceable or can be resurfaced with an inexpensive reseating tool.
How do I know my faucet brand?
Look for a name on the handle cap, escutcheon, or the side of the body. No name visible? The cartridge shape itself identifies most major brands at the parts counter.
Is a dripping faucet an emergency?
Rarely, but it is money and water down the drain every hour, and a drip at the base can quietly rot the cabinet floor. Fix it within days, not months.