Low Water Pressure? Here Are the Most Common Causes

Few things start the day worse than a weak, dribbling shower. Low water pressure has many possible causes — some you can fix in minutes, others that need a plumber. Here is how to narrow it down.

Is It One Fixture or the Whole House?

This first question tells you a lot. If only one faucet or shower is weak, the problem is local. If pressure is low everywhere, the cause is likely in your main supply, pressure regulator, or the municipal supply.

Common Single-Fixture Causes

• Clogged aerator — mineral buildup on the faucet tip; unscrew and clean or replace it
• Blocked showerhead — soak in vinegar to dissolve deposits
• Partially closed valve — check the shut-off under the sink is fully open

Whole-House Causes

• Pressure regulator failure — a faulty regulator can drop pressure across the home
• Corroded or clogged pipes — older galvanized pipes narrow with buildup over time
• A hidden leak — water escaping before it reaches your fixtures
• Main shut-off not fully open — sometimes the simplest fix

Quick Things to Check Yourself

Start with the easy wins: clean aerators and showerheads, confirm all shut-off valves are fully open, and check whether neighbors have the same issue (which would point to the municipal supply). If you have a pressure gauge, healthy home pressure typically falls in the 40 to 60 psi range.

When to Call a Professional

If cleaning fixtures and opening valves does not help, or if pressure drops suddenly across the whole house, call a plumber. Sudden whole-home pressure loss can signal a burst or leaking line, and a failing regulator or corroded piping needs professional replacement. Catching a hidden leak early also prevents water damage and high bills.