# Low water pressure in one faucet: clean the aerator

Updated: 2026-10-24 · https://pros411.com/en/guides/plumbers/low-water-pressure-faucet

## Short answer

When only one faucet is weak, the aerator at the tip is usually clogged with grit or mineral crust. Close the drain, then unscrew the aerator by hand, counterclockwise as you look up at it. Rinse it, soak the parts in white vinegar for 30 minutes and scrub the screen with an old toothbrush. Screw it back on hand-tight. Still weak? Check that the shut-off valves under the sink are fully open.

## How to clean a clogged faucet aerator

![Cartoon sink with a weak trickle and a clogged faucet aerator under a magnifier](https://pros411.com/img/guias/low-water-pressure-faucet.webp)

1. **A weak, sputtering stream from one faucet.** The other faucets work fine. That points to this faucet, and most often to the little screen at its tip.
2. **Cover the drain and unscrew the aerator.** Lay a towel in the sink. Turn the tip counterclockwise as you look up at it. If it is stuck, wrap it in tape and use pliers gently.
3. **Look at the screen: grit and mineral crust.** Sand, rust or white scale block the tiny holes. Take a photo before you separate the parts so they go back in order.
4. **Soak it in white vinegar, then scrub.** Leave it 30 minutes, or overnight if the crust is thick. Scrub with an old toothbrush and rinse. Run the faucet a few seconds without it.
5. **Screw it back on by hand.** Snug, not tight. Open the faucet: the stream comes out full and smooth again.

## If the aerator is hidden

Many newer faucets have a recessed aerator with nothing to grip. It comes out with a small plastic key, often included with the faucet, or with an aerator key from the hardware store. Pull-down kitchen sprayers have a screen too: unscrew the spray head from the hose and clean the screen inside.

## Why it happens

- Grit and rust come loose after repairs on the water main or a shutoff in your area.
- Hard water leaves white scale that closes the holes little by little.
- Only the hot water is weak at every faucet? That points to the water heater, not the aerator.
- Weak everywhere, hot and cold? Check the main water valve and call your water company.

## When to call a plumber

- The aerator is clean and the stream is still weak (the cartridge or the supply line may be clogged).
- Water pressure is low in the whole house.
- The shut-off valve under the sink will not open all the way.
- The aerator is stuck and the spout is starting to bend or scratch.

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## Frequently asked questions

### Why does only one faucet have low water pressure?

Almost always a clogged aerator, the little screen at the tip. A shut-off valve that is partly closed or a clogged cartridge are the next suspects.

### How do I remove a faucet aerator?

Turn it counterclockwise as you look up at it, by hand first. If it is stuck, wrap it in tape or a rag and use pliers gently so you do not crush it.

### How long do I soak an aerator in vinegar?

About 30 minutes for light scale, or overnight if the holes are crusted white. Then scrub with an old toothbrush and rinse well.

### Can I just leave the aerator off?

For a day, yes, but put it back. Without it the water splashes, and on most faucets more water comes out than you need.

### Should I replace the aerator instead of cleaning it?

Replace it if the screen is torn, the plastic is cracked or the crust will not come off. Take the old one to the store to match the size and thread.