How to Fix a Leaky Faucet (Step by Step)

Learning how to fix a leaky faucet is one of the most useful home repairs you can do yourself, because a faucet that drips once every few seconds can waste more than 3,000 gallons of water in a year and quietly add to your water bill month after month. The good news is that most leaks come from a worn washer, O-ring, or cartridge, and those parts cost only a few dollars at any hardware store. You do not need to be a plumber to handle this job. With basic tools, about an hour of patience, and the steps below, you can stop the drip, protect your sink and cabinet from water damage, and avoid paying for a service call for a simple fix.

What Causes a Faucet to Leak?

A faucet leaks when water finds a path past a seal that is supposed to hold it back. In older compression faucets, a rubber washer presses against a metal valve seat every time you turn the handle. Over thousands of uses, that washer hardens, cracks, or wears unevenly, so water slips past even when the handle is fully closed. In newer ball, disc, and cartridge faucets, the same idea applies: O-rings dry out, cartridges develop grooves, and mineral deposits from hard water build up on sealing surfaces. Loose parts can also cause trouble. A packing nut that has worked loose, a handle screw that is not snug, or a cartridge that was installed slightly out of alignment can all let water seep out around the handle or spout.

Where the water appears tells you a lot about the cause. A drip from the spout usually points to a worn washer or cartridge inside the valve. Water leaking around the base of the faucet or under the handle often means a failed O-ring or loose packing. A leak under the sink is a different problem and usually involves a supply line, a drain connection, or a loose mounting nut rather than the faucet valve itself. Before you buy parts, note your faucet brand, model, and type. Take a photo of the faucet and of the cartridge once you remove it. Hardware stores stock many similar-looking parts, and bringing the old part with you is the surest way to leave with the right replacement. If your home has very hard water, you may also see white mineral crust on the aerator or valve parts, which can be cleaned with vinegar while you have the faucet apart.

Tools and Parts You Will Need

You do not need a large toolbox for this repair. Gather an adjustable wrench, a set of Allen keys, flathead and Phillips screwdrivers, needle-nose pliers, plumber grease, white vinegar, a soft cloth, and a small container to hold screws and parts in order. A basin wrench helps if you need to work under the sink, but most faucet repairs happen from above. For parts, start with replacement washers, O-rings, or a cartridge that matches your faucet. Many manufacturers sell repair kits that include all the seals for one model, and these kits are often cheaper and more reliable than buying single washers and guessing at sizes. Keep the packaging and receipt until the repair is tested, in case you need to exchange a part.

Lay a towel in the sink and keep a phone nearby to photograph each step as you disassemble the faucet. Those photos are your reassembly guide. Work in good light, and avoid forcing anything. Faucet parts are often brass or plastic, and a stripped screw or cracked handle will turn a small repair into a replacement job. If a screw is stuck, a drop of penetrating oil and a few minutes of patience usually frees it. If a decorative cap covers the handle screw, pry it gently with a thin flathead screwdriver wrapped in cloth so you do not scratch the finish. For more background on faucet types, see our faucets and fixtures hub and our guide to fixing low water pressure at a faucet.

Step 1: Shut Off the Water

Start by turning off the water supply to the faucet. Look under the sink for two shut-off valves, one for hot and one for cold, and turn both clockwise until they stop. If your sink has no shut-off valves or the valves are stuck and leaking, turn off the main water supply to the house instead. Then open the faucet to release pressure and confirm the water has stopped. Let the faucet drain fully into the sink. This step takes only a minute, but skipping it guarantees a wet cabinet, a soaked towel, and a much harder repair. Never try to remove a cartridge or washer while the supply is still on.

While the water is off, check the shut-off valves themselves. If a valve drips when you turn it, or if the handle spins without stopping the flow, the valve may need replacement too. That is a separate job, but it is worth noting now, because a failing shut-off valve will make every future faucet repair harder. If you must use the main shut-off, tell everyone in the household so no one turns on a tap or starts the washing machine mid-repair. Once the faucet runs dry, plug the drain with a stopper or rag. Small screws and springs love to disappear down drains, and a plugged drain saves you from fishing for parts or calling a plumber for a lost piece.

Step 2: Plug the Drain and Disassemble

With the water off and the drain plugged, remove the handle. Most handles have a small screw hidden under a decorative cap marked hot or cold, or under a set screw on the underside of the handle. Remove the cap carefully, unscrew the handle screw, and lift the handle straight off. If the handle sticks, wiggle it gently side to side rather than pulling hard. Under the handle you will find a retaining nut, a bonnet nut, or a retaining clip that holds the cartridge or stem in place. Remove that nut or clip with an adjustable wrench or pliers, keeping pressure steady so you do not scratch the finish. Place every part on your towel in the order you removed it.

Pull the cartridge or stem straight out, noting its orientation. Many cartridges have a notch or tab that must line up the same way when you reinstall them. If you install a cartridge backward, hot and cold may reverse, or the faucet may not shut off fully. Photograph the cartridge from two angles before you remove any O-rings from it. If the faucet is a compression type with separate hot and cold handles, you will instead find a stem with a washer held on by a small screw at the bottom. Remove that screw, slide the washer off, and inspect the valve seat inside the faucet body. A rough or pitted valve seat will chew up a new washer quickly, so run your fingertip lightly over it. If it feels rough, a valve-seat wrench and a replacement seat can fix it, or a plumber can resurface it.

Step 3: Replace the Washer or Cartridge

Match the old part exactly before you install anything new. Compare the washer diameter and thickness, the O-ring size, and the cartridge length and spline pattern. If you are using a repair kit for your exact model, follow its instructions and replace all the seals at once, not just the one that looks worst. Seals age together, and replacing only one often means taking the faucet apart again in a few months. Coat new O-rings lightly with plumber grease. This silicone-based grease keeps rubber flexible, helps seals seat properly, and makes future removal easier. Do not use petroleum jelly on rubber seals, because it can degrade some types of rubber over time.

Clean the inside of the faucet body while it is open. Soak mineral deposits in white vinegar, wipe away grit with a soft cloth, and rinse. Do not use abrasive pads inside the valve bore, because scratches create new leak paths. Slide the new cartridge or stem in with the same orientation you photographed, and reinstall the retaining nut or clip snugly. Do not overtighten plastic parts, which can crack, or brass nuts, which can distort seals. If your faucet has an aerator on the spout, unscrew it, rinse out sediment, and reinstall it. A clogged aerator can mimic a pressure problem after a repair, and cleaning it now saves a second troubleshooting round. Our kitchen faucet buying guide can help if you decide the faucet is too far gone to repair.

Step 4: Reassemble and Test

Reinstall the handle and its screw, then replace any decorative cap. Turn the water supply back on slowly, starting with the cold side, and watch for leaks around the handle, base, and under the sink. Open the faucet fully and let it run for a minute to flush out any debris loosened during the repair. Then close it firmly and watch the spout. A few drops in the first minute can be leftover water in the spout, but a steady drip after five minutes means something is still not sealing. If the drip continues, turn the water off again and recheck the cartridge orientation, the washer seating, and whether the retaining nut is snug. Most repeat leaks come from one of those three causes.

Test both hot and cold sides separately if you have two handles, and check the temperature direction. If hot and cold are reversed after a cartridge replacement, the cartridge is installed 180 degrees off, and rotating it will fix the problem. Wipe the faucet dry, then check again after an hour and again the next morning. Slow leaks sometimes take time to show, especially around O-rings that need to swell slightly and seat. Keep your old parts and packaging for a few days in case a seal fails early. Once the faucet holds dry overnight, the repair is done. Clean up, remove the drain plug, and enjoy a quiet sink. If you are weighing repair against replacement, our comparison of touchless versus touch faucets covers modern options worth considering.

Repair Costs and When to Call a Plumber

Doing this repair yourself is inexpensive. Washers and O-rings usually cost 3 to 10 dollars, a repair kit runs 10 to 30 dollars, and a replacement cartridge typically costs 15 to 60 dollars depending on brand. A plumber will usually charge 150 to 350 dollars for a standard faucet repair, including parts and labor, and more if shut-off valves also need replacement. The table below gives realistic 2026 US ranges for common scenarios.

Call a plumber if the faucet body is cracked, the valve seat is badly pitted, shut-off valves fail, or water is leaking inside the wall or cabinet where you cannot see the source. Also call for help if you have already replaced the cartridge and the drip persists, because the problem may be a damaged valve body that no seal can fix. For most homeowners, though, one careful hour with the steps above ends the drip for years. If you need professional help, call (877) 762-1902 to discuss your faucet repair.