Short definition

A leaking faucet drips from the spout, base, or handle even when the handles are fully closed. The fix is almost always a worn rubber seal, O-ring, or cartridge. Where it leaks tells you which part to replace — most repairs are a 30-minute, $5-$25 DIY job once you’ve identified the faucet brand and type.

What it is

A faucet leaks because something inside it stopped sealing. The drip location isolates the failure:

  • Spout drip with handles off — the main shutoff seal is worn. In a compression faucet (two-handle, pre-1980), that’s a rubber seat washer. In a cartridge faucet, it’s the cartridge or its O-rings. In a ball faucet, it’s the springs and seats. In a ceramic-disc faucet, it’s the cartridge cylinders.
  • Base of spout when faucet is on — spout O-rings worn; pull the spout off and replace.
  • Handle leak when faucet is on — stem packing or escutcheon O-ring worn.
  • Under-sink leak at supply connection — supply-line gasket or worn nut.

Identify the brand (Delta, Moen, Pfister, Kohler, American Standard) and the type before buying parts. Most rebuild kits are brand-specific, and the wrong cartridge is a wasted trip to the hardware store.

A 1-drip-per-second leak wastes about 5 gallons a day, or 1,800 gallons a year — enough to bump a Seattle water bill noticeably.

Why it matters to a homeowner

Most faucet leaks are DIY. The rebuild kit costs $5-$25, the work takes under an hour, and the savings — water bill, porcelain stains, and not paying a service-call minimum — make this one of the highest-ROI plumbing repairs in the home. The exception is a stuck cartridge in a hard-water area: Spokane and Sammamish homeowners often find calcified ceramic-disc cartridges that won’t pull out without a special tool, and a plumber’s $150 service call beats breaking the faucet body.

When a plumber says they’ll “rebuild the cartridge” or “replace the seats and springs,” they’re naming the same parts you’d buy at a hardware store. The labor is the bulk of the bill on a service call.

Common failure modes

  • Worn rubber seat washer. Compression faucets in pre-1980 WA homes. Cheapest fix.
  • Worn spout O-ring. Single-handle and two-handle faucets after 5–10 years.
  • Calcified ceramic-disc cartridge. Hard-water areas (Spokane, Eastside well systems). Often needs replacement, not rebuild.
  • Failed ball, springs, and seats. Single-handle ball faucets (Delta-style) — kit includes everything.
  • Loose packing nut. Tighten before replacing anything.
  • Hose-bib stem packing. Outdoor faucet leak at the handle — replace the packing or the whole stem.

Common variants

  • Leaking faucet vs. leaking valve. A faucet leak is at the fixture; a valve leak is the under-sink stop or main shutoff. Different parts, different repairs.
  • Spout drip vs. base seep. Different mechanisms — the seat seals against the body in compression, but the spout O-rings seal against the spout shaft. Don’t replace the wrong one.
  • Stuck cartridge vs. leaking cartridge. Different problems. A stuck cartridge won’t shut off fully (constant trickle); a leaking one drips intermittently.

Washington note

Hard-water areas in Eastern WA and the Eastside (Sammamish, Issaquah, Redmond on private wells) calcify ceramic-disc cartridges fast. If you’re in a hard-water area, expect to replace cartridges every 5-10 years instead of rebuilding the original. Soft Cedar/Tolt water in Seattle is gentler on cartridges but harder on metal seats — pre-1990 compression faucets in Seattle homes show pitted brass seats from soft acidic water. Both situations are still DIY, just different parts.

SPU and Tacoma Water distribute free faucet aerators and showerheads through the Saving Water Partnership; while you’re rebuilding, swap the aerator too.