How to Fix Low Water Pressure in Sink

How to Fix Low Water Pressure in the Sink

Low water pressure in a sink is frustrating — but it's almost always caused by something simple. Here's how to diagnose and fix it yourself in minutes.

Step 1: Check If It's Just This Sink

• Only one sink has low pressure: The problem is localized — likely a clogged aerator or partially closed valve
• Multiple fixtures have low pressure: The problem is with your home's water supply. See our guide on How to Fix Low Water Pressure in the Whole House

Cause 1: Clogged Faucet Aerator (Most Common)

The aerator is the small screen at the tip of the faucet spout. It mixes air into the water stream and filters debris. Over time, mineral deposits and sediment clog it, dramatically reducing flow.

Fix:

1. Unscrew the aerator from the faucet tip (counterclockwise by hand, or use a rubber strap wrench if it's tight)
2. Disassemble the aerator — it has a screen, washer, and housing
3. Soak all parts in white vinegar for 30 minutes to dissolve mineral deposits
4. Scrub with a small brush and rinse thoroughly
5. Reassemble and reinstall — hand-tight only
6. Turn water on and test — pressure usually improves immediately

If the aerator is heavily corroded or damaged, replace it — they cost $2–5 at any hardware store.

Cause 2: Partially Closed Shut-Off Valve

The hot and cold shut-off valves under the sink may not be fully open:

1. Look under the sink for the two shut-off valves on the supply lines
2. Turn both fully counterclockwise (open)
3. Test the faucet — pressure should improve immediately if a valve was partially closed

Cause 3: Kinked or Corroded Supply Line

The braided supply lines under the sink can kink or corrode internally, restricting flow:

1. Check the supply lines for kinks or sharp bends
2. If kinked, straighten them out
3. If corroded or old, replace the supply lines — they're inexpensive and easy to swap

Cause 4: Debris in the Faucet Cartridge

Sediment can get past the aerator and lodge in the faucet cartridge, restricting flow. If cleaning the aerator doesn't help, the cartridge may need cleaning or replacement using a faucet stem repair kit.

Cause 5: Low Hot Water Pressure Only

If only the hot water has low pressure, the issue may be with your water heater — a partially closed inlet valve or sediment buildup in the heater. Check that the water heater inlet valve is fully open.

Bottom Line

Low sink pressure is almost always a clogged aerator — clean it first, it takes 5 minutes. If that doesn't fix it, check the shut-off valves and supply lines. Most sink pressure problems are solved in under 15 minutes without any special tools.