If the stream from a kitchen or bathroom faucet looks orange, or the tip of the spout has a crust that matches, the small metal screen inside the faucet tip is a good place to look first. This part, called an aerator, mixes air into the water and helps keep the flow smooth. In St. Louis homes, where iron can show up in some water supplies and older pipes can shed rust particles, the screen often catches flecks that would otherwise pass straight through.

What an Aerator Does and Why It Clogs

An aerator is a cap with a fine mesh screen that threads onto the spout. Water passes through the screen and leaves as a smooth, airy stream. The mesh also traps sediment. Iron particles, mineral scale, and bits of pipe debris collect on the screen over time. As the openings narrow, the flow weakens, sputters, or sprays off to one side.

Signs the Aerator Is the Problem

  • The flow is weak or uneven at one faucet but normal at others.
  • The stream sputters or sprays in several directions.
  • Orange or brown flecks appear in the water from just that faucet.
  • The screen or the inside rim of the spout has an orange film or crust.

Narrow It Down First

Before you take anything apart, run each faucet on its own and compare the hot and cold lines at the same sink. If only the hot side shows orange, the water heater or the hot water piping may be part of the story, and the aerator is only one piece of it. If both sides show it at one sink while other sinks in the house run clear, the aerator is a likely cause. If every faucet in the house runs orange, the problem is more likely in the water supply itself, and it is worth checking the source before you clean fixtures one by one.

For St. Louis homeowners on city water, the water provider publishes an annual water quality report. Read it for iron mentions, but keep in mind that it describes water at the treatment plant, not the water after it has traveled through your service line and house pipes. Well owners in the area will get a clearer answer from a private test of their own water.

Cleaning an Aerator Step by Step

  1. Clear the sink area and place a towel in the basin so small parts cannot fall down the drain.
  2. Look at the spout tip. Most aerators unscrew by hand. If it is stuck, wrap a cloth around it and use gentle pliers.
  3. Note the order of the parts as you remove them. Aerators often stack a washer, a screen, and a housing in a specific order.
  4. Rinse each piece under running water, pushing from the back of the screen toward the front to force debris out.
  5. Use a soft brush to loosen crust. Avoid wire brushes and steel wool, which can scratch the finish and leave marks of their own.
  6. If mineral or iron deposits are stubborn, soak the parts in a mild household vinegar solution for a while, then rinse them well.
  7. Reassemble the parts in the same order and screw the aerator back onto the spout by hand.

When to Replace Instead of Clean

Some screens are bent, torn, or so crusted that they will not hold their shape after cleaning. Replacement aerators are usually easy to find at hardware stores, but match the thread size and the spout type before you buy. If the screen clogs again soon after cleaning, the particles are probably coming from a steady source, and it is time to look at the water supply, a sediment filter, or the pipes feeding the fixture.

What to Do Next

Clean the aerator, run the faucet, and see whether the flow and color improve. If the water still runs orange at every fixture, test the water. Home iron test kits give a general reading, while a lab gives a more precise answer. Keep the aerator screen and any sediment you remove, since it can be a useful clue when you describe the problem to a testing lab or a plumber.