Short definition

A faucet that drips from the spout when shut off has a worn internal seal — what’s worn depends on the faucet type. For compression faucets, the rubber stem washer or the brass seat. For ball-valve faucets, the rubber seats and springs. For cartridge faucets, the cartridge. For ceramic-disc faucets, the discs (usually scored by grit from the supply line).

What it is

Spout drips are the highest-volume faucet repair search and the most common single homeowner faucet symptom. The diagnostic walks by mechanism:

  • Compression faucet (older two-handle). Worn rubber stem washer is the cheap fix ($3). If the drip persists with a new washer, the brass seat is pitted — replace it (or grind it flat).
  • Ball-valve faucet (older Delta/Peerless single-handle). The two rubber valve seats and their springs in the inlet ports have worn. A standard Delta RP4993-style repair kit is $15.
  • Cartridge faucet (modern single-handle). Replace the cartridge. $20 to $60.
  • Ceramic-disc faucet (modern long-life). Discs rarely wear; a drip means grit scored them. Replace the cartridge AND flush the supply lines, or the new cartridge will fail too.

Why it matters to a homeowner

A faucet dripping at one drop per second wastes about 5 gallons per day, or 1,800 gallons per year (EPA WaterSense math). On a hot-water tap, that’s measurable money in heating cost on top of the water bill. Saving Water Partnership and most WA utilities have leak-detection campaigns specifically because residential faucet drips are the most common preventable household water loss.

The repair is honest DIY for almost every faucet type. Identify the mechanism (single handle that rotates and tilts = ball or cartridge; two separate handles = compression; lifetime-warranty single-handle = ceramic disc), then match the fix.

When you’ve replaced a compression washer twice and it still drips, stop replacing washers — the seat is the problem.

Common variants