How to Fix Low Water Pressure at a Faucet
Updated February 25, 2026
Diagnose and fix low water pressure at a single faucet -- clogged aerator, blocked supply valve, kinked line, or cartridge restriction.
Overview
Low pressure at one faucet while other fixtures flow normally is a local problem -- not a house-wide pressure issue. Something between the shut-off valve and the faucet spout is restricting flow. The aerator is the most common culprit. Mineral deposits, sediment, and debris collect in the screen and gradually choke flow. The fix takes 2 minutes: unscrew the aerator, rinse it, put it back. If the aerator is clean, the problem is deeper -- a partially closed valve, kinked supply line, or clogged cartridge.
What You'll Need
Safety First
- You do not need to turn off the water to clean or replace the aerator. Just unscrew it from the spout tip.
- If you need to check the supply lines or cartridge, turn off both supply valves under the sink first.
Step-by-Step Instructions
- Clean the Aerator (Fix 70% of Cases)
Unscrew the aerator from the end of the faucet spout. Turn it counterclockwise by hand or with pliers wrapped in tape (to avoid scratching the finish). Inside the aerator housing: a screen, a flow restrictor disc, and sometimes a rubber washer. Rinse everything under running water. Use a toothbrush or pin to clear clogged screen holes. Soak in white vinegar for 30 minutes if mineral deposits are heavy. Reassemble and screw back on. Test flow.
Tip: If you cannot remove the aerator by hand, wrap it in a vinegar-soaked rag for 15 minutes. The acid dissolves the mineral bond holding it on. Then try again. Pliers with a rubber jaw protector work if it is really stuck. - Check the Supply Valves
Look under the sink. Both supply valves (hot and cold) should be fully open. Gate valves (multi-turn): turn counterclockwise all the way until they stop. Quarter-turn ball valves: handle should be parallel to the pipe (perpendicular = off). A partially closed valve restricts flow significantly. If the valve is stiff and will not open further, it may be seized -- do not force it or it may break.
Tip: If only hot OR cold is low pressure (not both), the problem is on that specific side. Check the supply valve, supply line, and cartridge for that side only. - Inspect the Supply Lines
Old chrome supply lines corrode internally, narrowing the flow path while looking fine outside. Braided stainless steel lines rarely have this problem. Turn off the supply valves. Disconnect the lines at the faucet end. Hold them over a bucket and briefly open the valve. Strong flow into the bucket = lines are fine, problem is in the faucet. Weak flow = the supply line is restricted. Replace old chrome or plastic lines with new braided stainless steel ($5-$8 each).
Tip: Check the rubber washers inside the supply line fittings. A displaced or swollen washer can partially block the opening and restrict flow. This is a common cause that mimics a bigger problem. - Check the Cartridge (If All Else Is Clear)
If the aerator, valves, and supply lines are all fine, the faucet cartridge itself may be clogged with debris. Remove the handle and pull the cartridge (see your faucet brand's instructions). Inspect the ports -- sediment or scale blocking the passages restricts flow. Clean with vinegar and a small brush. If the cartridge is old and gunked up, replace it ($10-$25 depending on brand). Reinstall and test.
Tip: New construction or recent plumbing work often introduces solder flux, pipe shavings, and debris into the water lines. This debris collects in the cartridge and aerator of the first faucet downstream. Flush lines before installing new faucets to prevent this.
Pro Tips
- Keep a spare aerator in the kitchen drawer ($3-$5). When one clogs beyond cleaning, swap it in seconds.
- If pressure is low at ALL faucets in the house, the problem is not local. Check the main shut-off valve (may be partially closed), the pressure reducing valve (may need adjustment), or contact your water utility for street-side pressure issues.
- Hard water above 7 grains per gallon clogs aerators every 3-6 months. A water softener eliminates this across all fixtures.
- Low-flow aerators (1.0-1.5 GPM) restrict flow by design to save water. If someone installed a low-flow aerator and you want more pressure, swap it for a standard 2.2 GPM aerator. That is not a malfunction -- it is a setting.
- After any plumbing work (water main repair, new water heater, re-piping), flush all faucets with the aerators removed for 30 seconds. This prevents construction debris from clogging the screens.
When to Call a Pro
Call a plumber if all faucets in the house have low pressure (whole-house issue needing PRV adjustment, main valve check, or utility investigation), if the supply valve under the sink is seized and will not open fully (valve replacement needed), or if the faucet has a non-removable internal flow restrictor that is clogged (some newer faucets have tamper-resistant flow limiters).
Frequently Asked Questions
When should I call a plumber to fix low water pressure at a faucet?
Call a plumber if all faucets in the house have low pressure (whole-house issue needing PRV adjustment, main valve check, or utility investigation), if the supply valve under the sink is seized and will not open fully (valve replacement needed), or if the faucet has a non-removable internal flow restrictor that is clogged (some newer faucets have tamper-resistant flow limiters).
What are some expert tips to fix low water pressure at a faucet?
Keep a spare aerator in the kitchen drawer ($3-$5). When one clogs beyond cleaning, swap it in seconds. If pressure is low at ALL faucets in the house, the problem is not local. Check the main shut-off valve (may be partially closed), the pressure reducing valve (may need adjustment), or contact your water utility for street-side pressure issues. Hard water above 7 grains per gallon clogs aerators every 3-6 months. A water softener eliminates this across all fixtures. Low-flow aerators (1.0-1.5 GPM) restrict flow by design to save water. If someone installed a low-flow aerator and you want more pressure, swap it for a standard 2.2 GPM aerator. That is not a malfunction -- it is a setting. After any plumbing work (water main repair, new water heater, re-piping), flush all faucets with the aerators removed for 30 seconds. This prevents construction debris from clogging the screens.
What tools do I need to fix low water pressure at a faucet?
You will need: Pliers with tape or rubber jaw protector (for removing the aerator), White vinegar (for dissolving mineral deposits), Toothbrush or pin (for cleaning aerator screen holes), Adjustable wrench (for supply line connections if needed), Bucket (for testing supply line flow).
When should I call a professional instead of doing this myself?
Call a plumber if all faucets in the house have low pressure (whole-house issue needing PRV adjustment, main valve check, or utility investigation), if the supply valve under the sink is seized and will not open fully (valve replacement needed), or if the faucet has a non-removable internal flow restrictor that is clogged (some newer faucets have tamper-resistant flow limiters).
How difficult is this project?
This project is rated easy. Most homeowners with basic tools can complete it.
How long does this take?
Plan for approximately 10 - 30 minutes. First-timers may need extra time.
How much will this cost?
The estimated cost is $0 - $15. Costs vary by location and materials chosen.