How to Fix Low Water Pressure at a Faucet (Clean the Aerator)
Short answer: If only one faucet has weak or sputtering flow, the aerator screen at the tip of the spout is probably clogged with sediment or mineral scale. Unscrew it, rinse and soak it in white vinegar, or replace it with a new aerator of the same size.
- Difficulty
- Easy
- Time
- 10 to 30 minutes
- Updated
- November 9, 2026
What is causing it?
The aerator is a small screen and flow restrictor in the tip of the faucet. Sediment, rust flakes and hard-water minerals build up on it, especially after water main work or plumbing repairs. If every fixture in the house is weak, the problem is upstream (a partly closed main valve, a failing pressure regulator, or a utility issue) and an aerator will not fix it.
Tools and materials
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Tools
- Channel-lock or slip-joint pliersWrap the jaws in tape to avoid scratching the finishCheck price on Amazon
- Aerator key, for recessed (cache) aeratorsMany newer faucets need oneCheck price on Amazon
- Old toothbrushCheck price on Amazon
Materials
- White vinegarCheck price on Amazon
- Replacement WaterSense aerator (match thread size)Bring the old one to match male or female threadCheck price on Amazon
- Painter's tape or a ragTo protect the faucet finishCheck price on Amazon
How do you clean a faucet aerator? Step by step
Confirm it is one faucet
Run the other faucets and the shower. If only this one is weak on both hot and cold, the aerator is the prime suspect.
Close the drain
Close the sink stopper or lay a rag in the basin so the small screens and washers cannot fall down the drain.
Unscrew the aerator
Turn it counterclockwise (as you look down from above) by hand. If it is stuck, wrap it with tape and use pliers gently. For recessed aerators, use the matching aerator key.
Take it apart and clean it
Note the order of the screen, flow restrictor and rubber washer. Rinse out debris, scrub with a toothbrush, and soak the parts in white vinegar for 30 minutes to an hour to dissolve mineral scale.
Flush the faucet
With the aerator off, run water for a few seconds to flush out loose debris from the spout.
Reinstall or replace
Put the parts back in order, screw the aerator on hand tight, and test. If the screen is damaged or the scale will not come off, install a new aerator of the same thread size and flow rate.
Safety notes
- Do not over-tighten the aerator; the threads on the spout are soft brass or plastic.
- If the faucet has a pull-down sprayer, check the sprayer head screen too.
When should you call a pro?
- The whole house has low pressure.
- Pressure dropped suddenly along with a hissing sound or a wet spot, which can mean a hidden leak.
- Only the hot side is weak at every faucet, which can point to a water heater shutoff or sediment problem.
Frequently asked questions
Will a new aerator lower my water pressure?
A WaterSense labeled aerator uses less water but is designed to still perform well. EPA WaterSense says swapping aerators for labeled models can save a household up to 700 gallons a year.
How often should I clean aerators?
Every few months in hard-water areas, and any time flow drops or water sputters after plumbing work.
Why is only the hot water weak?
At one faucet it can be a clogged cartridge on the hot side. At every faucet it can be the water heater's supply valve or sediment in the tank.
Sources
Steps are based on these manufacturer and safety references. Your product's own manual comes first.