Why Is My Water Pressure Low?

4 Common Flow Problems & Fixes

You turn on your shower expecting a strong, steady stream, but instead get a disappointing trickle. Or your kitchen faucet barely produces enough water to rinse dishes properly. It's frustrating, and like most homeowners, you probably describe this as "low water pressure."

But what you're experiencing probably isn't necessarily a pressure problem. Understanding the difference between water pressure and water flow will save you time, money, and unnecessary repairs.

Core Concepts: Water Pressure vs. Water Flow Rate

Water Pressure and Flow Rate are correlated but not identical. Understanding the difference is key to determining what the actual problem is and how to fix it.

Water Pressure (PSI) is the force pushing water through your pipes. It's measured in pounds per square inch. Normal household fixtures are designed to operate at 40-70 PSI. PSI stands for pounds per square inch. This is a measure of how much force is pushing against the inside of the pipes and up against the fixtures when the water is NOT flowing.

Water Flow Rate (GPM) is the volume of water that actually comes out of your faucet or shower. It's measured in gallons per minute. This is what you experience when you turn on the tap.

You need adequate pressure for good flow, but you can have perfectly normal pressure (60 PSI) and still get weak flow if something is restricting the water. In fact, you can have dangerously high water pressure inside your pipes and still experience low flow rate. This is a very common occurrence for many residents of the Charlotte area.

A clogged aerator is a perfect example: your pipes have plenty of pressure, but the blockage prevents water volume from reaching you. That's why most "low-pressure" complaints are actually flow restrictions, not pressure problems.

The good news? Flow restrictions are usually easier and cheaper to fix than true pressure problems. And although Charlotte Mecklenburg Water isn't considered “hard” by any standard, there are still plenty of particulates that can enter and clog the plumbing system from the municipal water supply during repairs and maintenance. If you have well water, that typically means you do have hard water and should definitely be utilizing a softening system.

4 Common Causes of Low Water Flow

1. Clogged Aerators & Showerheads

This is by far the most common cause of weak water flow. The aerator is the small screen attachment at the tip of your faucet that shapes the water stream. Over time, mineral deposits and tiny debris particles collect inside these openings, blocking the water and reducing your flow to a trickle.

When this is your problem: One fixture has weak flow while others work normally. You might notice white or greenish buildup on the aerator screen.

DIY Fix:

Unscrew the aerator from the faucet tip (usually turns counterclockwise when looking at it from underneath). Most newer faucets have a toothed inner aerator that requires a specific sized aerator tool to remove without damaging it.
Soak it in white vinegar for about an hour
Use an old toothbrush to scrub away visible deposits
Rinse thoroughly under running water
Reinstall and test your flow

For showerheads, the process is similar - unscrew, soak, scrub, and reinstall.

Call a professional if: The aerator is corroded or damaged and needs replacement, you can't remove it without risking damage to your fixture, or the problem persists after cleaning.

2. Clogged Faucet Cartridge Stem

Inside your faucet handle sits a cartridge (older faucets typically have stems) that controls water flow. These internal components can accumulate debris and mineral deposits over time, especially in single-handle faucets where one cartridge controls both temperature and flow.

When this is your problem: Flow gradually decreases over weeks or months at a single fixture. Cleaning the aerator doesn't help. You might also notice the handle feels different when turning.

The Solution: Replacing faucet cartridges varies from simple to complex depending on your faucet brand and model. Some homeowners successfully handle this repair, but many prefer professional service to avoid the hassle of identifying the correct cartridge or potentially damaging expensive fixtures or piping. A plumber can quickly diagnose the issue, have the right replacement parts, and complete the repair without risk to your faucet or piping. In most cases it's a better use of time and money to replace the faucet altogether with one your plumber considers to be good quality.

3. Partially Closed or Debri Ridden Shutoff Valves

Every fixture has small shutoff valves underneath (under sinks) or behind it (behind toilets). These valves allow you to stop water flow for repairs without shutting off your whole house. Sometimes these valves get left partially closed after maintenance work or inspections, restricting your flow without you realizing it. Often they accumulate debris from the plumbing system, particularly multi-turn stops which utilize rubber washers.

Your home also has a main shutoff valve where water enters -sometimes near your water heater or in a basement. If this valve isn't fully open, or if it is collecting debris and build up it can affect your entire house's flow.

DIY Fix:

Check under sinks and behind toilets - turn valve handles fully counterclockwise (Don’t Force!)
Locate and check your main water shutoff valve
Test your flow after ensuring all valves are fully open

Call a professional if: Any valve is stuck and won't turn (forcing it can cause leaks), you notice corrosion or water around the valve, or you can't locate your shutoff valves.

4. Clogged Water Filter or Softener

If you have a whole-house water filter or softener system, dirty cartridges or clogged resin beds can significantly restrict flow throughout your entire home. These systems process all the water entering your house, so when they become clogged, every fixture suffers.

Diagnostic Test: Most filter systems have a bypass valve. Temporarily bypass your filter system and test your water flow. If flow improves dramatically, your filter needs attention.

The Solution: Filter cartridges should be replaced according to the manufacturer's schedule—usually every 3-6 months depending on your water quality and usage. If you can't locate your filter housing, the bypass valve is unclear, or you have a complex whole-house treatment system, professional service ensures proper maintenance and optimal performance.

Diagnosing Low Water Pressure or Low Flow

Before you start taking things apart, a systematic approach will help you identify the problem quickly:

Step 1: Single Fixture or Multiple Fixtures?

If only one faucet or shower has weak flow: Start with the aerator or showerhead
If multiple fixtures have weak flow: Look at filters, water heater especially tankless models (if only hot), or consider true pressure issues

Step 2: Hot Water, Cold Water, or Both?

Only hot water is weak: Water heater inlet filter (tankless only) or shut off valve to water heater is your likely culprit
Only cold water is weak: Check that specific fixture's aerator and shut off valve
Both hot and cold are weak: Aerator, main shutoff valve, filter, or possible pressure issue

Step 3: Check the Simple Things First

Clean aerators on affected fixtures (5 minutes, costs nothing)
Verify all shutoff valves are fully open - both fixture valves and main shutoff
Check when you last replaced your whole-house filter cartridge
Look around fixtures and under sinks for any visible leaks

Step 4: When It Might Be a True Pressure Problem

If you've checked everything above and ALL fixtures throughout your entire house are affected equally, you might have an actual pressure problem rather than a flow restriction. Common causes include failing pressure-reducing valves, municipal supply issues, or significant hidden leaks.

True pressure problems require different diagnoses and solutions. A professional plumber can test your actual pressure with a gauge and determine if you need pressure-specific repairs.

Get Your Water Flow Back to Normal

Most homeowners who search for "why is my water pressure low" are actually dealing with flow restrictions, not pressure problems. The distinction matters because flow restrictions usually have simpler, more affordable solutions - and many you can tackle yourself.

Start with the basics: clean your aerators, check your valves, and replace your filters. These simple fixes solve the majority of flow issues. If you've tried the obvious solutions and still have weak flow affecting multiple fixtures, that's when it's time for a professional diagnosis.

If you've followed these steps and still can't pinpoint the issue, you're not alone - many plumbing problems require professional diagnostic tools and experience to solve correctly.

Experiencing weak water flow throughout your home? Contact Pathmaker Plumbing for straightforward diagnosis and practical solutions. We'll explain exactly what's happening with your plumbing system and walk you through your options clearly - no pressure, just honest answers. Call (704) 733-7507.