How to Fix a Leaky Faucet — Step by Step for Every Faucet Type

A dripping faucet wastes up to 3,000 gallons of water per year — roughly enough to fill a swimming pool — and can stain fixtures, encourage mold growth, and drive up your water bill by $20 or more each month. The good news: most faucet leaks are caused by a single worn-out internal part (a washer, O-ring, cartridge, or ceramic disc) that costs $3–20 and takes 15–60 minutes to replace, depending on your faucet type.

What Causes a Leaky Faucet?

Every faucet uses internal seals to stop water flow when you turn the handle off. Over time, these seals wear out from friction, mineral buildup, and normal use. The specific part that fails depends on your faucet type — and identifying the type is the most important first step, because it determines which part you need to buy before you start the repair.

There are four common faucet types in residential homes:

Compression faucets are the oldest and simplest design — they have two separate handles (one hot, one cold) that you tighten to close. Inside, a rubber washer presses against a metal valve seat to stop water flow. These washers flatten, crack, or harden over time, and the valve seat itself can become pitted from corrosion. If you have two handles that require pressure to turn fully off, you almost certainly have a compression faucet.

Ball faucets use a single handle that moves freely in all directions — side to side for temperature and up/down for volume. Inside, a slotted metal or plastic ball rotates over spring-loaded rubber seats. The springs lose tension and the seats wear down, allowing water to seep through. Ball faucets are common in kitchens and are most easily identified by the rounded cap directly under the handle.

Cartridge faucets have a single handle that moves in a smooth up/down arc (or two handles with a smooth quarter-turn). Inside is a self-contained cartridge with O-rings that create the seal. Cartridges are brand-specific — Moen, Delta, Kohler, and Pfister all use different sizes and shapes — so you need to bring the old cartridge to the hardware store for an exact match.

Ceramic disc faucets are the newest and most durable design. They use two ceramic plates that slide against each other — one fixed, one that moves with the handle. Leaks are usually caused by sediment buildup between the discs or worn seals around the cylinder. Ceramic disc faucets typically have a wide, flat handle on a broad base.

Tools and Materials You'll Need

Don't buy parts until you've identified your faucet type and — for cartridge and ceramic disc faucets — removed and inspected the old component. Take the worn part to the hardware store to match it exactly. Universal kits rarely fit properly.

How to Fix a Leaky Faucet (Step by Step)

These steps work for all faucet types. Where the process differs by type, the step will note it.

1. Identify your faucet type. Before touching anything, figure out what you're working with. Two separate handles that tighten = compression. Single handle that moves in all directions = ball. Single handle that moves up/down in an arc = cartridge. Wide single handle on a broad flat base = ceramic disc. Your faucet brand and model number are usually stamped under the sink or on the base of the faucet.
2. Shut off the water supply. Look under the sink for the two shutoff valves (one hot, one cold). Turn them clockwise until fully closed. Then open the faucet to release pressure and drain the remaining water from the line. If your shutoff valves are stuck or you don't have them, shut off the main water supply to the house instead.
3. Protect the workspace. Close the sink drain or cover it with a rag — small screws and springs will disappear down an open drain. Lay a towel in the basin to catch parts and prevent scratching. As you disassemble the faucet, lay each part in order on the counter and take a photo for reference during reassembly.
4. Remove the faucet handle. Most handles have a decorative cap (a small plastic or metal cover on top) — pry it off gently with a flathead screwdriver to reveal the screw underneath. Remove the screw (it may be a Phillips head, flathead, or Allen/hex screw). Pull the handle straight up and off. If the handle is stuck from mineral buildup, don't force it — wrap a vinegar-soaked cloth around the base for 15 minutes, or use a hair dryer on low heat to loosen the deposits.
5. Remove the packing nut or retaining hardware. Under the handle, you'll see a large nut (packing nut), retaining clip, or threaded cap holding the internal mechanism in place. Use your adjustable wrench to loosen the packing nut (try both directions — some faucets tighten counterclockwise). For cartridge faucets, look for a small U-shaped retaining clip on the side — pull it out with pliers.
6. Remove and inspect the internal component. This is where the process diverges by type:
   
   Compression: Unscrew the stem and look at the rubber washer at the bottom. If it's flat, cracked, hardened, or deformed, that's your problem. Also inspect the brass valve seat inside the faucet body — if it's pitted or rough, water will leak past even a new washer. A pitted seat can be smoothed with a seat-grinding tool ($10) or you may need to replace the seat.
   
   Ball: Lift out the ball and inspect the rubber seats and springs in the holes below. Replace all of them — buy a complete ball faucet repair kit ($8–15) rather than individual parts, since the springs and seats wear at similar rates.
   
   Cartridge: Pull the cartridge straight up and out (some require a cartridge puller tool, ~$10). Inspect the O-rings on the outside of the cartridge — if they're cracked, flattened, or nicked, they need replacing. If the cartridge body itself is worn or corroded, replace the entire cartridge. Bring the old one to the store — cartridges are brand- and model-specific.
   
   Ceramic disc: Lift out the cylinder and check the seals on the bottom. Clean any sediment or mineral buildup off the ceramic discs with white vinegar and a soft cloth. If the seals are worn or the discs are cracked, replace the entire cylinder.
7. Install the new parts. Apply a thin coat of plumber's grease to all rubber O-rings and seals before installing — this extends their life and improves the seal. Insert the new component, making sure it's properly aligned (ball faucets have a small tab that must fit into a notch in the body). Tighten the packing nut or retaining clip hand-tight, then a quarter-turn with the wrench. Do not overtighten — this is the most common reassembly mistake and can crack the new parts or strip the threads.
8. Reassemble and test. Replace the handle, decorative cap, and screw. Open the faucet handle fully, then slowly turn the shutoff valves back on. The faucet may sputter briefly as air clears the line — this is normal. Once water flows steadily, turn the handle off and watch for drips at the spout and around the handle base for at least 60 seconds. If you see drips at the base of the spout rather than from the tip, the issue is likely worn O-rings on the faucet body — you'll need to remove the spout and replace those separately.

Troubleshooting: Still Dripping After the Repair?

If the faucet still leaks after you've replaced the internal parts, check these common issues:

Wrong part size. Even a slightly wrong washer, O-ring, or cartridge will leak. Bring the old part to the store and match it exactly — don't rely on "universal" kits.

Damaged valve seat. On compression faucets, the brass valve seat inside the faucet body can become pitted or corroded. A new washer pressed against a rough seat will still leak. Use a seat-grinding tool to resurface it, or replace the seat entirely.

Overtightened packing nut. Cranking down the packing nut too hard can deform the new seal. Back it off and retighten to hand-tight plus a quarter turn.

Leak is from the supply line, not the faucet. Check the connections under the sink where the supply lines meet the shutoff valves and the faucet tailpieces. Tighten with a wrench or replace the supply lines if the ferrules are worn.