A faucet that drips once per second wastes over 3,000 gallons of water per year. The good news: most faucet leaks are caused by a worn washer or O-ring that costs under $2 and takes less than an hour to replace. This guide covers the two most common faucet types found in homes.
Before buying parts, identify what kind of faucet you have:
This guide focuses on the compression faucet (most common leak type) and cartridge faucet (most common in newer homes).
Look under the sink for the shutoff valves — one for hot, one for cold. Turn them clockwise until they stop. Turn on the faucet to release any remaining water pressure and confirm the water is fully off. Place a bucket under the sink just in case.
If there are no shutoff valves under the sink, turn off the main water supply for the house.
Put the drain stopper in or lay a rag over the drain. Small screws and parts love to fall down drains.
Look for a decorative cap on top of the handle — pry it off with a flathead screwdriver to expose the screw underneath. Remove the screw (usually Phillips head), then pull or wiggle the handle off. If it’s stuck, don’t force it — spray a little WD-40 around the base and wait 5 minutes.
Under the handle, you’ll see a packing nut — the large hexagonal nut holding the stem assembly. Use an adjustable wrench to unscrew it counterclockwise. Pull the stem straight up and out. At the bottom of the stem, you’ll find a rubber washer held by a brass screw. This washer is almost always the cause of the leak.
Inspect the washer: if it’s flat, hardened, cracked, or has a groove worn into it, it’s the problem. Unscrew the brass screw, pop out the old washer, and replace it with an identical one. Coat the new washer lightly with plumber’s grease. Replace the brass screw.
While you have the stem out, inspect the O-ring on the side of the stem body. If it’s cracked or worn, replace it too.
For cartridge faucets, once the handle is removed, you’ll see a retaining nut or clip holding the cartridge. Remove it, then pull the cartridge straight up — use pliers if needed. Take the cartridge to the hardware store to find an exact replacement (or search the faucet brand online for the part number).
Insert the new cartridge with the tabs aligned with the body slots. Reassemble in reverse order.
Reassemble everything in reverse order: stem back into the body, packing nut tightened (don’t overtighten — snug plus a quarter turn), handle back on, decorative cap back in place. Slowly turn the shutoff valves back on and let pressure build. Turn on the faucet and check for leaks.
If there’s still a small leak from around the base of the spout, the body O-rings need replacement. If the faucet still drips from the spout, the valve seat may be damaged and needs professional resurfacing or the faucet should be replaced.
Most faucet repairs are DIY-friendly, but consider calling a plumber if:
A simple washer replacement costs a few dollars and 30 minutes. Putting it off can mean a water damage bill that runs into the thousands. Fix the drip today.