Why Is My Water Pressure Low? Causes and Fixes

By Ishaq Khokhar. Updated October 3, 2026. 3 min read.

Short answer: If only one faucet or shower is weak, a clogged aerator or showerhead is the usual cause. If the whole house has low pressure, check that the main shut off valve is fully open, then look at the pressure regulator, a hidden leak, old corroded pipes, or a problem on the water supplier’s side.

Weak water pressure makes showers frustrating and appliances slow. The good news is that many causes are simple to fix. If you are asking why is my water pressure low, this guide explains the most common causes and how to find yours.

Step 1: Is it one fixture or the whole house?

One fixture: the problem is usually in that faucet, showerhead or its supply valve.
Hot water only: the problem may be the water heater, such as sediment or a partly closed valve.
The whole house: the problem is in the main supply, the regulator, the pipes or the supplier.

Illustration of a copper pipe joint spraying water onto a stained wall — Leaking joints can soak walls and floors before anyone notices.

Fixes for one fixture

Unscrew the faucet aerator and rinse out grit and mineral scale.
Soak a showerhead in white vinegar for a few hours to dissolve scale.
Check that the shut off valves under the sink are fully open.
Replace an old cartridge in a faucet or shower valve if flow stays weak.

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Causes of low pressure in the whole house

Main shut off valve partly closed: often after recent plumbing work.
Pressure reducing valve: many homes have a regulator near the main valve that can wear out or be set too low.
A hidden leak: water escaping from a supply line or slab leak lowers pressure.
Old galvanized pipes: corrosion builds up inside and narrows the pipe over time.
Water supplier issues: main breaks, maintenance or high demand in your area.
Well pump problems: for homes on a well, the pump or pressure tank may need service.

Illustration of a sink full of standing water that will not drain — A drain that will not empty often means a blockage further down the line.

Check for a leak

Turn off every tap and appliance, note the water meter reading, wait an hour and check again. If it moved, you likely have a leak. Read our guide to slab leak signs and about leak detection.

Ask your neighbors

If neighbors also have low pressure, the problem is probably with the water supplier. Contact them for updates on repairs or maintenance.

When water pressure is too high

Pressure that is too high, often above about 80 psi, can be just as harmful. It stresses pipes, fittings, water heaters and appliances, and can cause leaks and banging pipes. A working pressure reducing valve keeps it in a safe range. If faucets spray hard or pipes bang when taps close, have the pressure tested.

When to call a plumber

Low pressure in the whole house with no supplier problem
You suspect a leak or the meter moves when water is off
Your home has old galvanized pipes
The pressure regulator needs adjusting or replacing
Pressure is too high, which can damage fixtures and cause leaks

Illustration of a rusty water heater leaking into a puddle on the floor — Rust streaks and water around the base mean a water heater may be failing.

A plumber can test the pressure with a gauge. Many homes aim for around 40 to 60 psi. Read about plumbing services.

Illustration of a leaking pipe dripping under a kitchen sink with a wrench and plunger nearby — Small drips under a sink can damage cabinets and floors over time.

Quick answers: why is my water pressure low

Why is my water pressure suddenly low?

Common causes are a partly closed main valve, a failing pressure regulator, a leak or a problem with the water supplier.

Why is only my shower pressure low?

Usually a clogged showerhead or an old valve cartridge. Soaking the showerhead in vinegar often helps.

Can a leak cause low water pressure?

Yes. Water escaping from a supply line or slab leak lowers pressure throughout the home.

What is normal home water pressure?

Many homes aim for around 40 to 60 psi. A plumber can test it with a gauge.

Who fixes low water pressure?

A licensed plumber. Sifixit can connect you with a local plumber.

This guide covered why is my water pressure low. For more background, see the EPA’s WaterSense program, and if you need help, Sifixit can connect you with a local provider.

This guide is general information for homeowners, not professional, insurance or safety advice for your situation.

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