What causes a faucet to drip?

A worn sealing part: a rubber washer on compression faucets, O-rings and seals on cartridges and balls, or fouled ceramic discs. Which part depends on which mechanism, which is why identifying the faucet type comes first.

Is it worth repairing a faucet or should I replace it?

Repair parts cost a few dollars against a faucet's much larger price, so repair wins on quality faucets with available parts. Replace when the body itself is corroded, the finish is failing, or parts for an off-brand cannot be identified.

Why does my faucet drip only sometimes?

Temperature and pressure change how a marginal seal seats. A washer that drips at night when pressure rises, or after hot use, is the same worn part telling the same story.

Why is my faucet still dripping after I replaced the washer?

The valve seat under the washer is pitted, chewing each new washer. Compression faucets need the seat dressed with an inexpensive seat wrench or grinder when washer replacement alone fails.

Leaking Faucet Repair: Cartridge, Ball, and Compression Types

Page last reviewed: August 2026 · Reviewed by Harold R. Bennett, retired home inspector

Every dripping faucet is one worn part asking for a few dollars, and knowing how to fix a leaking faucet starts with a single identification question: which of the four mechanisms is under the handle? Compression, cartridge, ball, or ceramic disc each drips from its own part and rebuilds its own way. This guide identifies, then repairs.

First, the universal preliminaries

Water off at the under-sink stops (or the main if the stops are seized, which is its own message), faucet opened to drain, drain plugged so screws cannot escape into it, and parts laid out in removal order, with phone photos at each step. The single most valuable habit: take the worn parts to the store, because faucet parts are matched by brand and model, not by looking similar.

Identify the mechanism

Two handles that tighten down with a squeezing feel: compression, the oldest design, a stem screwing down to press a rubber washer against a seat. Older houses, utility sinks, and hose bibs.

One handle on a dome that moves in an arc: ball faucet (Delta’s classic), a slotted ball over spring-loaded seats.

One handle that lifts and swings, or two handles that turn a smooth quarter-plus: cartridge, the modern majority, a replaceable cylinder doing all the work, the same component logic as the shower valve family.

One or two handles with a crisp, short quarter-turn: ceramic disc, the premium design, two polished discs shearing across each other.

Compression: washer and seat

The drip means the washer; the repeat drip means the seat. Pull the handle, unscrew the packing nut, extract the stem, and replace the beveled washer at its base plus the O-ring on the stem (the O-ring cures leaks at the handle rather than the spout). If a new washer drips within weeks, the brass seat below is pitted and sandpapering each washer to death: a seat wrench swaps replaceable seats, and a seat dresser grinds fixed ones smooth, both inexpensive tools that end the washer subscription.

Cartridge: the swap

Handle off, retaining clip or nut off, cartridge out, matched cartridge in. The two complications are extraction and orientation: mineral-seized cartridges want the brand’s puller rather than pliers-and-fury, since cracking the faucet body converts a small repair into a replacement, and reversed installation swaps hot and cold, which is a message to pull and rotate, not a defect. Hard-water houses can expect cartridge service as a recurring rhythm, one more line in scale’s household ledger.

Ball: the kit

Ball faucets wear their springs, seats, and O-rings as a set, so they are rebuilt as a set: the brand’s repair kit includes the seats, springs, cam, and often the ball. Cap off, cam out, ball out, then fish the two rubber seats and springs from their sockets (spring orientation matters: narrow end up into the seat), reassemble per the kit. Drips from the spout are the seats and springs; leaks at the base are the spout O-rings, serviced by lifting the spout sleeve on the way past.

Ceramic disc: clean before replacing

Disc faucets rarely wear out; they get gritty. Debris and scale between the discs holds them fractionally open, so the first repair is disassembly and cleaning of the disc faces and the inlet seals beneath the cylinder, which cures most drips. Genuinely damaged cylinders swap like cartridges. One caution unique to the type: after any water shutoff, open disc faucets gently, because trapped air slamming across ceramic can crack a disc, the small cousin of water hammer.

The judgment calls

Repair beats replacement wherever the brand is identifiable and the body sound, which covers most quality faucets for decades. Replacement wins when the body or finish is corroding, the faucet is a parts-orphan, or the under-sink stops and supply lines are due anyway, at which point the whole assembly renews together. And any faucet that drips from the body itself, not the spout or handle, has finished its career.

The bottom line

Identify the mechanism, replace its wearing part with the matched part, dress the seat when washers keep dying, clean discs before condemning them, and let photos and the parts bag do the remembering. A drip is a few dollars and half an hour; the same drip ignored is a water bill with a rhythm section.