How to Fix a Dripping Faucet: Washers, Cartridges, and Common Causes

17. August 2026

A faucet that keeps dripping after you turn it off usually has a worn seal, debris inside the valve, or a damaged cartridge. The right repair depends on what controls the water inside your faucet. Before buying parts, find exactly where the leak starts and identify the faucet’s mechanism. Those two checks can save you from replacing a part that was working perfectly well.

Find Where the Water Is Leaking

Dry the faucet, countertop, and accessible pipes beneath the sink. Run the water briefly, turn it off, and watch where moisture first appears.

Dripping from the spout while the faucet is off: Suspect the internal shutoff parts, such as a compression washer, cartridge, or spring-loaded seat.
Water around the handle: A stem seal, O-ring, packing, or cartridge seal may be leaking.
Water around a swivel spout’s base: Worn spout O-rings are a common cause, especially when the leak appears during use.
Water beneath the sink: Check supply hoses, shutoff valves, and faucet connections. If it appears only while the sink drains, inspect the drain plumbing too.

A few drops immediately after use can be water draining from the spout. A drip that continues after that remaining water has drained suggests a sealing problem.

The EPA’s WaterSense home maintenance guidance recommends checking faucets for drips and inspecting beneath sinks for leaking connections, puddles, and water spots.

A dirty aerator usually causes weak flow or uneven spray. Cleaning it will not normally fix a dripping faucet when water is passing through a faulty internal valve.

Identify Your Faucet Type

Handle movement offers clues, but confirm the mechanism using the manufacturer’s model information or parts diagram.

Faucet type	Typical clues	Common repair
Compression	Usually separate hot and cold handles that turn several times	Replace the rubber washer; inspect the valve seat
Cartridge, including ceramic-disc designs	One or two handles; often smooth movement or a short turning range	Replace the compatible cartridge or specified seals
Ball valve	Often an older single-handle faucet with a rounded cap beneath the handle	Replace the specified seats, springs, and seals; inspect the ball

Two handles do not automatically mean the faucet uses compression washers. Many two-handle faucets use cartridges, and some use separate rubber seats and springs beneath the stems.

For a rental home, report the leak to the landlord or property manager before disassembling the fixture.

Gather Tools and Match the Replacement Part

Most small faucet repairs need:

Screwdrivers and appropriately sized hex keys
An adjustable wrench
A flashlight, towels, and a small parts tray
The correct washer, cartridge, or repair kit
Manufacturer-approved lubricant, if the instructions require it

Find the brand and model number on the faucet, supply-line tag, original paperwork, or purchase record. Use the manufacturer’s parts diagram to identify the replacement number.

For faucet cartridge replacement, appearance alone is unreliable. Similar cartridges can have different lengths, locating tabs, seal arrangements, or handle connections. Some two-handle models also require different hot- and cold-side parts.

If identification requires removing the old part, photograph it and take it to a plumbing supplier. Match compression washers by diameter, thickness, profile, and fixing hole. Keep the water isolated while the faucet is disassembled.

Shut Off the Water Before Taking Anything Apart

Clear the cabinet so you can reach the shutoff valves comfortably. Locate the home’s main shutoff as well, in case an under-sink valve does not work.

Close both hot and cold supply valves. Multi-turn valves generally close clockwise; quarter-turn valves usually close with the handle perpendicular to the pipe.
Open the faucet. On a single-handle mixer, move it through hot and cold positions to release pressure and check both supplies.
Wait for the flow to stop. A little remaining water is normal. Continuous flow means the supply is not fully isolated.
Cover the drain and lay out a towel. This catches small screws and protects the sink.

Do not force a seized shutoff valve. If it will not close, starts leaking, or leaves water flowing continuously, stop before removing any faucet retaining parts. Arrange a reliable shutoff or get plumbing help.

Replace the Faulty Sealing Parts

Follow the instructions for your particular model. Handle fixings, retaining systems, and tightening requirements vary.

Replacing a Compression Washer

A compression faucet closes by pressing a rubber washer against a valve seat inside the faucet body.

Remove the handle. Carefully lift any decorative cap, remove the screw, and lift off the handle.
Remove the stem assembly. Loosen the appropriate bonnet or retaining nut and withdraw the stem as directed. Keep wrench pressure on the intended flats and avoid twisting the faucet or supply connections.
Inspect the washer. Look for cracks, hardening, flattening, or a deep groove. Remove its fixing screw, if fitted.
Fit the matching replacement. Seat it evenly and secure it without distorting the rubber.
Inspect the valve seat. This is the surface the washer presses against. Gently remove loose debris; a rough, pitted, or cracked seat can make a new washer leak again.
Reassemble the faucet. Keep the stem backed away from its fully closed position while reinstalling it, then refit the handle.

A damaged valve seat may need replacement or specialist repair. Avoid grinding or resurfacing it without confirming that the faucet supports that procedure.

Afterward, close the handle gently. Excessive force compresses the new washer and can shorten its life.

Replacing a Faucet Cartridge

A cartridge contains the moving parts that regulate flow and, in many single-handle faucets, mix hot and cold water.

Remove the handle and trim. Photograph each layer as you work.
Record the cartridge orientation. Note locating tabs, markings, and the stem position.
Remove the retainer. Depending on the model, this may be a clip, nut, or mounting screws.
Extract the cartridge as instructed. Some pull straight out; others need a manufacturer-specified removal tool. Avoid levering against the faucet body.
Clean the housing gently. Remove loose debris with a soft cloth and inspect the sealing surfaces.
Install the exact replacement. Align its tabs and ports, keeping seals flat and untwisted.
Refit the retainer completely. Then reinstall the trim and handle.

Do not restore the water until the cartridge is fully secured. If a retaining clip will not fit, check cartridge seating and alignment instead of forcing it.

Use lubricant only where the manufacturer specifies it. When required, use the supplied product or an approved silicone lubricant suitable for drinking-water fittings. Leave factory-lubricated parts as supplied unless instructed otherwise.

Repairing a Ball-Valve Faucet

Ball-valve faucets commonly use rubber seats supported by springs beneath the ball. A compatible repair kit may include these parts, along with a cam seal and O-rings.

Record the assembly order, replace the specified components, and follow the model’s instructions for spring orientation and cap adjustment. Inspect the ball for damage. Compression-washer instructions do not apply to this mechanism.

Turn the Water Back On and Check the Repair

Remove tools and loose parts from the sink. Set the faucet as directed by its repair instructions, then reopen the supply valves slowly.

Run cold water, followed by hot water, and check that the handle moves correctly. If the manufacturer recommends flushing with the aerator removed, do so after the valve assembly is fully secured.

Dry everything again and check:

The spout after the faucet is closed and residual water has drained
Around the handle and spout base while water runs
Supply connections and shutoff valves beneath the sink
Any joints disturbed during the repair

Press dry tissue against accessible connections to reveal small leaks. Check again after several minutes and after the next few uses.

If the Faucet Still Drips

Shut the water off again before reopening the assembly. Check the part number, cartridge orientation, seal placement, and any separate seats or springs shown in the parts diagram.

A new washer that leaks again quickly can point to a damaged valve seat. Persistent cartridge leaks can result from trapped debris, an incorrectly seated seal, or damage inside the faucet body. Thread tape will not repair these internal sealing faults.

Get plumbing help if the cartridge is seized, the body is cracked or badly corroded, or you cannot isolate the water reliably. Once the correct parts seal properly, the faucet should shut off with normal, gentle handle pressure.