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Fix a faucet that has low pressure

We'll confirm the symptom, clean the aerator, check the supply valve, inspect the cartridge, or tell you when to call a plumber.

Troubleshooting · Home plumbing
10–25 min
What you'll need
  • White vinegar (for soaking aerator)
  • Old toothbrush
  • Cloth or rubber glove (for grip)
  • Replacement cartridge (if needed; match faucet brand and model)
Step 1 of 6

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Steps

Goal: Confirm the symptom, clean the aerator, check the supply valve, inspect the cartridge, or call a plumber.

  • Turn on the hot and cold water at the affected faucet. Compare with other faucets.
  • Good: Only this faucet has low pressure—proceed to Clean the aerator.
  • Bad: All faucets are weak—possible main supply issue; call a plumber.

Clean the aerator

Goal: Remove mineral buildup from the aerator. It is the most common cause of low pressure at a single faucet.

  • Turn off the hot and cold supply valves under the sink. Open the faucet to release pressure.
  • Unscrew the aerator from the faucet spout (counterclockwise). Use a cloth or rubber glove for grip.
  • Soak the aerator in white vinegar for 15–30 minutes. Scrub the screen and holes with an old toothbrush. Rinse and reinstall.
  • Turn the supply valves back on and test. Good: Pressure improved—done. Bad: Still low—proceed to Check supply valve.

Check supply valve

Goal: Confirm the supply valve is fully open. A partially closed valve restricts flow.

  • Check the hot and cold supply valve under the sink. Turn counterclockwise until fully open.
  • Good: Both valves fully open—proceed to Inspect the cartridge if pressure is still low.
  • Bad: Valve is stuck or leaking—do not force it; call a plumber.

Inspect the cartridge

Goal: Check the cartridge for wear or mineral buildup. Replace if needed.

  • Shut off the water. Remove the handle and trim. Pull the cartridge.
  • Inspect for mineral buildup or damage. Soak in vinegar if buildup is light, or replace with an exact match if damaged.
  • Reassemble the faucet and turn the water back on. Confirm the pressure has improved.

When to get help

Call a plumber if:

  • You have cleaned the aerator, confirmed the supply valve is open, and replaced the cartridge but pressure is still low.
  • The supply valve is stuck or leaking.
  • Multiple faucets have low pressure (possible main or supply issue).
  • You suspect a supply-line blockage.

Verification

  • Water flows with normal pressure from the faucet.
  • Hot and cold both have adequate flow.
  • No leaks at the aerator or supply connections.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify low pressure at this faucet only.
  2. Clean aerator Remove, soak, scrub, and reinstall the aerator.
  3. Check supply valve Confirm the supply valve is fully open.
  4. Replace cartridge Inspect and replace the cartridge if worn or clogged.
  5. Call a plumber Supply valve stuck, supply-line blockage, or pressure still low after steps.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Whether the aerator was cleaned
  • Whether the supply valve was checked
  • Whether the cartridge was replaced
  • Steps already tried

Is low pressure only at this faucet?

Compare flow at this faucet with others in the house. Single-faucet low pressure points to aerator, supply valve, or cartridge.

Turn on hot and cold at this faucet and others. Only this faucet: proceed to clean aerator. All faucets: possible main supply issue; call a plumber.

Yes No (all faucets)

You can change your answer later.

Did cleaning the aerator improve pressure?

Remove the aerator, soak in vinegar, scrub, reinstall. Test the flow.

Shut off supply valves. Remove the aerator, soak in vinegar 15–30 min, scrub with toothbrush, reinstall. Turn water back on. Improved: done. Still low: check supply valve.

Yes No

You can change your answer later.

Pressure restored

The aerator was the cause. Pressure should be normal. If it worsens again, clean the aerator periodically.

Done

Is the supply valve fully open?

The supply valve under the sink must be fully open for full pressure.

Check the hot and cold supply valve under the sink. Turn counterclockwise until fully open. Fully open: proceed to cartridge. Stuck or leaking: call a plumber.

Yes No (stuck)

You can change your answer later.

Did replacing the cartridge improve pressure?

A worn or clogged cartridge can restrict flow.

Shut off water. Remove handle and trim, pull the cartridge. Inspect for buildup or damage. Replace with exact match if needed. Reassemble and test. Improved: done. Still low: call a plumber.

Yes No

You can change your answer later.

Call a plumber

Call a plumber if all faucets have low pressure, the supply valve is stuck or leaking, you have tried aerator and cartridge and pressure is still low, or you suspect a supply-line blockage.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why does my faucet have low pressure?
Usually the aerator is clogged with mineral deposits or debris. The supply valve under the sink may be partially closed. A worn cartridge can also restrict flow. Clean the aerator first—it fixes most cases.
Can I fix low faucet pressure myself?
Yes. Cleaning the aerator takes a few minutes and requires no special tools. Checking the supply valve and replacing the cartridge are also DIY for most people. Call a plumber if you cannot access the supply valve or the faucet continues to have low pressure after these steps.
When should I call a plumber for low faucet pressure?
Call a plumber if only one faucet has low pressure and you have cleaned the aerator, confirmed the supply valve is open, and replaced the cartridge but pressure is still low. Also call if you suspect a supply-line blockage or if multiple faucets have low pressure (possible main or supply issue).

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