Repairs

How to fix a dripping faucet, and when to stop

Most faucet drips come down to one worn part inside the valve, and a homeowner with a hex key can deal with it. The trouble starts under the sink, where a shut-off valve from the 1970s decides whether the job is an hour or a flood.

Updated August 20, 2026 ·Our services

How to fix a dripping faucet, and when to stop

A drip from the spout end is a worn seal inside the valve. On most faucets made in the last thirty years that means a cartridge, and swapping one takes under an hour with an adjustable wrench, a hex key and the right replacement part. Water arriving from anywhere else is a different story. The base of the spout, under the handle, the connections below the sink, or a damp patch in the cabinet floor each point at their own cause, and two of them can soak a cabinet or a wall before you notice. So the first job is not buying parts. It is working out where the water is actually leaving the fixture.

Dry it off and watch where the water appears

Take a towel to everything under and around the faucet until it is bone dry, then run the tap for a minute, shut it off and watch for another few minutes. Faucets leak in four places, and each place points at a different set of parts.

A drip from the spout after the handle is fully closed means the seal inside the valve no longer seats, which is a cartridge, a pair of seats and springs, or a set of ceramic discs depending on the design.

Water seeping around the base of the spout where it meets the sink deck usually means the O-rings on the spout body have gone hard, and those are a much smaller set of parts than the valve itself.

Water showing under the handle only while the tap runs points at the bonnet nut, the packing under it, or a cracked cartridge body.

A wet cabinet floor under a faucet that looks dry on top is a supply connector, an angle stop or the sink drain, and not the faucet at all.

That last one catches people out more than any other. A slow weep from a braided supply connector runs along the line, tracks sideways under the sink base and drops off at the lowest point, which can be a good distance from where it started. Follow the water uphill with your fingers before you take anything apart.

The four kinds of faucet, and why it decides the repair

Buying parts before identifying the design is how a one-hour job turns into three trips. Look at the handles and how they move.

Compression

Two handles that keep turning and tighten down at the end of travel. A rubber washer on a threaded stem presses onto a brass seat. Replacing the washer is the oldest DIY plumbing repair there is, but if the seat has been scored by grit the new washer will not hold either, and you need a seat wrench or a dressing tool to sort it out.

Ball

A single lever that swivels over a domed body. Under the cap sits a slotted ball with small springs and rubber seats beneath it. Repair kits are sold for the common brands, but the springs are tiny, they drop into the drain given the chance, and the cam has to be aligned to the notch on reassembly.

Cartridge

One sealed insert doing all the sealing and mixing. You pull the handle, remove a retaining clip or nut, pull the old cartridge straight up and push the new one in. This is the easiest of the four and the most common on newer fixtures. The catch is that cartridges are brand specific and often model specific.

Ceramic disc

Two polished discs sliding against each other inside a cylinder. Almost nothing wears out. When one of these drips it is usually grit or mineral scale sitting between the disc faces, or the rubber inlet seals underneath the cylinder have flattened.

Local water puts scale where the seals live

Mesa Water District supplies most of Costa Mesa entirely from local groundwater, drawn from nine wells into the Orange County basin. Groundwater carries dissolved mineral, and mineral comes out of solution wherever water sits still and dries out. That is exactly the environment inside an aerator screen, on a ceramic disc face, and around the top of a cartridge.

So a faucet that has gone weak and drippy at the same time is often scaled rather than worn. Unscrew the aerator, soak it in white vinegar, brush the screen and refit it before you order a cartridge. If the flow comes back and the drip stops, you have found it. If the flow comes back and the drip stays, at least you now know which part is at fault.

The valve under the sink is what stops most DIY repairs

Costa Mesa housing has a median build year of 1972, and roughly two thirds of it went up before 1980. That means a lot of original angle stops still in service: multi-turn valves with a rubber washer inside that has been compressed in one position for decades. They seize. Worse, they half close, so you think the water is off, and then the faucet body fills while you have it in pieces.

Test yours before you touch anything else. Close the stop, open the faucet fully and wait a minute. If the flow stops dead and stays stopped, carry on. If it trickles, or if the stem starts weeping at the packing nut while you turn it, stop there. The stop needs replacing first, and that job needs the house main closed, which on a house of that vintage carries its own small adventure.

When to put the tools down

The angle stop will not close fully, or the main shut-off will not close, or the main is buried and you cannot find it.

The threaded nipple coming out of the wall turns as a unit when you loosen the supply nut, which means it can snap off inside the wall.

The leak is at a tub or shower valve rather than a sink faucet, because that valve body is inside the wall and often soldered to the pipes.

The cabinet floor has gone soft under your hand, or there is a musty smell, which means the water has been running for longer than you thought.

You have the cartridge out and the brass bore it sits in is pitted or grooved, because no new cartridge seals against a damaged body.

Water is showing on a ceiling below an upstairs bathroom, which is never a faucet job by the time it gets that far.

Three things to do before you take the handle off

Put a rag or a drain plug in the sink so a screw, a spring or a retaining clip cannot disappear down the waste.

Photograph the cartridge in place before you pull it, because most of them are keyed and fitting one rotated the wrong way reverses hot and cold.

Take the old part with you to the counter rather than trusting a model number stamped somewhere unreadable, since manufacturers change internals across production runs.

One last habit worth forming: when you finish, write the faucet brand and the cartridge part number on a strip of masking tape and stick it inside the cabinet door. The next time it drips, and it will eventually, the whole diagnosis is already done.