Fixing a Faucet with Low Water Pressure

Diagnosing the Problem

If only one faucet has low pressure while others work fine, the issue is localized to that fixture. Common causes include a clogged aerator, blocked supply lines, a partially closed shut-off valve, or a failing cartridge. If multiple fixtures are affected, the problem may be with your pressure regulator, main shut-off valve, or municipal supply. Test by removing the aerator and turning on the faucet — if pressure improves, the aerator was the issue.

Cleaning the Aerator

Unscrew the aerator from the faucet spout by hand or with pliers (wrap the aerator in tape to prevent scratches). Disassemble the aerator components and soak them in white vinegar for several hours or overnight to dissolve mineral deposits. Use an old toothbrush to scrub each screen and component. Rinse thoroughly and reassemble. If the aerator screens are corroded beyond cleaning, replace the entire aerator — they are inexpensive and available at any hardware store.

Checking Supply Lines and Valves

Verify that the shut-off valves under the sink are fully open by turning them counterclockwise until they stop. Older gate valves can become partially seized in a half-open position. Inspect the supply lines for kinks, especially flexible braided lines that may have been pinched during installation. If supply lines are old corrugated chrome, replace them with braided stainless steel lines which provide better flow and resist corrosion.

Cartridge and Valve Issues

If the aerator is clean and valves are fully open, the faucet cartridge or internal valve may be clogged with mineral deposits or debris. Remove the cartridge according to your faucet type and soak it in vinegar. For single-handle faucets, debris can lodge in the valve body itself — flush it out with water while the cartridge is removed. If cleaning does not restore full pressure, replace the cartridge with a manufacturer-specified replacement.