Fix Low Water Pressure in Your Kitchen Sink

Low water pressure at your kitchen sink is one of those problems that feels small until you're trying to fill a pot or rinse dishes and nothing happens. The kitchen sink takes a beating—it runs constantly, handles both hot and cold water, and collects sediment and mineral deposits that other fixtures often miss. What makes this repair approachable is that most causes live in the first few inches of pipe, the aerator, or the shutoff valve under the sink. You won't need a plumber for this. You'll need patience, a wrench, and maybe a screen and some vinegar. The payoff is immediate: water that flows like it should, a sink that works, and the knowledge that you fixed it yourself.

1. Strip and Soak the Screen. Locate the aerator—the cylindrical screen component at the tip of your faucet spout. Unscrew it by hand (turn counterclockwise), or wrap it in a cloth and use a wrench to gently loosen it if it's stuck. Once removed, rinse it under running water from another sink to dislodge loose debris. If the screen looks clogged with white or tan mineral buildup, soak the entire aerator in white vinegar for 30 minutes, then scrub the screen with an old toothbrush to remove mineral deposits. Rinse thoroughly and screw it back on hand-tight.
2. Test Valve Responsiveness. Look under your sink and locate the two shutoff valves mounted on the wall or pipes—one for hot water (usually on the left), one for cold (on the right). Turn each valve clockwise as far as it will go without forcing it, then turn it back counterclockwise about three-quarters of a turn. This seated position is the normal operating position. If either valve feels stuck or crunchy when you turn it, or if you notice water dripping from the valve stem, that valve may be partially blocking flow or failing internally. A stuck valve often means mineral buildup inside—turn it slightly open and closed several times to work it loose.
3. Isolate the Culprit. Turn off both shutoff valves completely by turning them clockwise until they stop. Place a towel or bucket under the supply lines to catch residual water. Using two adjustable wrenches—one to hold the fitting at the shutoff valve, one to turn the supply line nut—loosen the connection between the shutoff valve and the supply line. Do this for both hot and cold lines. Once disconnected, hold each supply line over a bucket and carefully turn the shutoff valve back on for a few seconds to flush the line. If water comes out weak or discolored, sediment is present in the lines. If flow is strong and clear, the blockage is elsewhere.
4. Push Out the Blockage. If discolored or weak water flowed from the supply lines in the previous step, sediment or mineral buildup is blocking flow. With both shutoff valves still off, use a piece of rigid wire (a straightened coat hanger works) or a plumbing snake to carefully push through the interior of each supply line toward the faucet. Do not force it—you're trying to dislodge mineral or sediment, not damage the line. Alternatively, if the supply lines are flexible and short, disconnect them at the faucet inlet (the part where they attach inside the cabinet), and run water backward through them into a bucket. Once you've flushed both lines, reconnect them hand-tight.
5. Reseal Without Stripping. Using two wrenches (one holding the valve fitting, one turning the supply line nut), tighten each supply line back onto its shutoff valve. Tighten firmly but do not overtighten—hand-tight plus a quarter turn is enough. Over-tightening strips the fitting and creates leaks. Make sure the rubber washer inside each nut is present and seated correctly before you tighten.
6. Reopen the Water Line. Turn each shutoff valve counterclockwise slowly—about three-quarters of a full turn—to open them. Do not turn them completely open (full counterclockwise); the valve should have slight resistance. This seated position allows you to shut off the water quickly if needed. Listen and watch for leaks at the supply line connections and at the valve itself. Let water run from the faucet for 30 seconds to clear any air in the lines.
7. Verify the Fix. Turn on the faucet fully and let it run for one minute. Feel the pressure on both hot and cold sides. Compare it to a bathroom sink or outdoor spigot to make sure flow is now normal. If pressure has improved significantly, the problem is solved. If pressure is still low on one side only (say, only the cold water is weak), the issue is isolated to that hot or cold line, and you may need to repeat the flushing step for that specific line.
8. Swap in a New Screen. If pressure is still low after cleaning the aerator and flushing supply lines, the aerator itself may be damaged or the internal screen may have holes or damage that cannot be cleaned. Unscrew the old aerator and take it to a hardware store to match the size (most are standard 15/16-inch or 55/64-inch). Purchase a replacement aerator rated for your faucet type (single-handle or double-handle) and screw it on hand-tight. Test the pressure again.
9. Spot Water Before It Spreads. Run the faucet for two minutes and visually inspect all connections under the sink: where supply lines connect to the shutoff valves, where they connect to the faucet inlet, and the valve stems themselves. Wipe each connection with a dry paper towel and watch for new moisture. If you see water dripping or weeping from any connection, turn off the water, tighten the nut a quarter turn, and test again. If the leak persists, the connection may need a new washer or the seal may be compromised.