If one faucet trickles while the rest of the house runs strong, don’t blame your water pressure — blame the aerator. I’ve cleared hundreds of these, and a clogged aerator is the single most common cause of low flow at a single fixture. It’s a five-minute fix with no tools and no plumber.
The aerator is the little screened cap screwed onto the tip of your spout. It mixes air into the stream and catches grit. Over time, mineral scale and debris clog that screen and choke the flow.
First: Is It the Aerator or Something Else?
Quick triage before you start:
| What you notice | Most likely cause | Fix |
|---|---|---|
| Low flow at one faucet only | Clogged aerator | Clean it (below) |
| Still weak after cleaning the aerator | Worn cartridge/valve | See fixing a dripping faucet |
| Low flow at every fixture | House-wide pressure issue | See low water pressure |
How to Clean a Faucet Aerator (Step by Step)
1. Unscrew the aerator. Most twist off by hand (turn clockwise as you look up at it). If it’s stuck, wrap the aerator in a cloth or a few wraps of tape to protect the finish and use slip-joint pliers — gently. Plug the drain first so nothing small falls in.
2. Take it apart and note the order. Inside you’ll find a screen, a flow restrictor, and rubber washers. Lay them out in order on a towel so reassembly is easy.
3. Soak in white vinegar. Drop the parts in a cup of vinegar for 30–60 minutes — overnight if it’s caked with hard-water scale. Then scrub the screen with an old toothbrush and rinse under running water.
4. Reassemble and hand-tighten. Put the parts back in the same order, thread the aerator on by hand, and snug it just past finger-tight. Run the faucet — flow should be back to full.
If you have hard water, this will keep happening. A fresh aerator costs a few dollars — keep a spare on hand. See our picks for a replacement faucet aerator, and if you’re upgrading the whole fixture, our best kitchen faucets and best bathroom faucets guides.
When It’s Not the Aerator
If you cleaned the aerator and flow is still weak at that faucet, the cartridge or stem inside the valve is worn or fouled — common on single-handle faucets. That’s a slightly bigger job but still DIY-friendly. If the whole house is weak, check your pressure-reducing valve and main shutoff instead.
Frequently Asked Questions
Why is water pressure low at only one faucet?
When low flow shows up at a single faucet and the rest of the house is fine, the problem is almost never your home’s water pressure — it’s a clogged aerator or cartridge at that one fixture. Start with the aerator; it’s the five-minute fix.
What do I soak a faucet aerator in?
Plain white vinegar. Soak the disassembled aerator parts for 30–60 minutes (overnight for heavy mineral scale), then scrub with an old toothbrush and rinse. Vinegar dissolves the calcium and lime that block the screen.
How often should I clean my faucet aerator?
Once or twice a year in hard-water areas, less if your water is soft. If you just had plumbing work or a new water heater installed, clean it sooner — debris knocked loose in the pipes collects in the aerator screen.
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