Short definition

A clogged aerator is the small mesh screen at the tip of a faucet that’s blocked with mineral scale, sediment, or debris — making the faucet trickle or sputter while the rest of the house runs fine. A 30-minute vinegar soak restores most of them. Spokane and Eastside hard-water homes need to clean aerators every 2–3 months.

What it is

The aerator is the screw-on tip on most kitchen and bathroom faucets — a fine mesh screen that mixes air into the stream and limits flow to the EPA WaterSense standard of 1.5 gallons per minute or less. It’s the smallest, most-restrictive opening in your fixture’s flow path, so it’s the first place buildup shows up.

When water at the aerator slows but other fixtures run normally, the aerator (or what’s stuck in it) is almost always the cause. Common buildup:

  • Limescale — white calcium-carbonate crust in hard-water areas (Spokane, Sammamish, Issaquah).
  • Sediment — orange/brown rust flakes after a water-main repair, hot-water-tank flush, or in pre-1960 galvanized homes.
  • Pipe-fitting debris — PEX shavings or solder fragments after recent plumbing work.
  • Failed dip-tube fragments — pre-1996 plastic dip tubes in old water heaters.

Cleaning workflow:

  1. Unscrew the aerator (most are 15/16”-27 male or 55/64”-27 female thread).
  2. Disassemble the screen, restrictor, and washer; note order for reassembly.
  3. Soak overnight in warm white vinegar.
  4. Brush the screen with an old toothbrush.
  5. Reinstall and test.

If the clog returns within weeks, the source is upstream — failed dip tube, sediment migration, or a corroded supply line.

Why it matters to a homeowner

A single-fixture pressure complaint that turns out to be a $0 vinegar fix is the best plumbing call no one made. Before scheduling a service appointment, unscrew the aerator and see if flow returns. If it does, you’ve isolated the problem in two minutes. SPU and Tacoma Water both distribute free WaterSense aerators (1.5 GPM) through the Saving Water Partnership — a simple swap from an older 2.2 GPM aerator that pays for itself fast.

Common failure modes

  • White mineral encrustation. Limescale; classic Spokane and Eastside pattern.
  • Rust-flake clogs. Pre-1960 galvanized homes, post-water-main work, or after a hot-water-tank flush.
  • Failed dip-tube fragments. Pre-1996 plastic dip tubes in old water heaters break apart and clog every aerator in the house.
  • Cartridge sediment trap. Some brands have a sediment cartridge behind the aerator — check that too.
  • PEX shavings or solder bits after recent install. First-fixture-after-shutoff sees the most.

Common variants

  • Clogged aerator (single fixture) vs. whole-house low pressure. A house-wide drop usually traces to the PRV, the softener, or the supply.
  • Aerator vs. cartridge. Different parts. Sometimes both need cleaning.
  • Aerator vs. flow restrictor. Modern aerators include a restrictor disc — check both.

Washington note

The cleaning cadence in Washington follows the water hardness:

  • Spokane / east of Cascades (7–13 GPG hardness): every 2–3 months.
  • Eastside Bellevue / Sammamish / Issaquah (8–15 GPG, Cascade Water Alliance): every 6 months.
  • Seattle / Tacoma / Olympia (Cedar/Tolt 1–2 GPG, very soft): annually or as needed.

Soft Cedar/Tolt water in Seattle rarely scales aerators — when a Seattle aerator clogs, suspect sediment from old galvanized or recent main work, not minerals. Hard-water households often install a water softener and watch the cleaning cadence drop dramatically.