Why Is My Water Pressure So Low? 7 Possible Causes
You turn on the shower and instead of a strong, steady stream, you get a disappointing trickle. Or maybe your kitchen faucet suddenly doesn't have the pressure it used to.
Low water pressure is frustrating, but it can also be a warning sign of a larger plumbing problem.
Sometimes the cause is a simple fixture issue. Other times, low pressure can point to a leak, damaged pipes, a problem with your water main, or another issue that requires professional attention.
Here are seven common causes of low water pressure and what you should know about each one.
1. A Clogged or Dirty Faucet Aerator
If the water pressure is low at only one faucet, start there.
Mineral deposits and debris can build up inside the faucet's aerator — the small screen at the end of the faucet. Over time, this buildup can restrict water flow.
This is one of the simplest causes to address.
Try this: Remove the aerator, clean it thoroughly, and reinstall it. If the water pressure improves, you've likely found the problem.
If pressure remains low, there may be another issue affecting that fixture.
2. A Partially Closed Shut-Off Valve
Every plumbing fixture typically has a shut-off valve that controls the water supply.
If the valve underneath your sink, behind your toilet, or near another fixture isn't fully open, it can restrict water flow.
This can happen after plumbing work, repairs, or even accidentally when items are stored underneath a sink.
Check the valve: Make sure it's fully open. Don't force a valve that is stuck or difficult to turn, as attempting to force an old valve can cause damage or a leak.
3. Mineral Buildup in Your Pipes
Older plumbing systems can develop mineral buildup inside the pipes. As deposits accumulate, they can gradually reduce the amount of water that can flow through the pipe.
You may notice that water pressure has slowly gotten worse over time rather than disappearing suddenly.
If multiple fixtures throughout your home have declining water pressure, mineral buildup or aging plumbing could be contributing to the problem.
A professional plumber can evaluate your plumbing system and determine whether the pipes themselves are restricting water flow.
4. A Hidden Plumbing Leak
A sudden drop in water pressure can sometimes be a sign of a leak.
If water is escaping somewhere in your plumbing system, less water may be reaching your faucets and fixtures.
Look for other warning signs, including:
Unexplained increases in your water bill
Damp or discolored spots on walls or ceilings
Water pooling around fixtures
The sound of running water when everything is turned off
Mold or musty odors
Areas of unusually wet soil outside
If you suspect a significant leak, don't ignore it. A hidden leak can cause extensive damage if left unaddressed.
5. A Problem With Your Pressure Regulator
Some homes have a pressure-reducing valve or pressure regulator that controls the water pressure entering the home.
When this component starts to fail, you may experience low or inconsistent water pressure throughout the house.
If you've noticed that multiple faucets and showers have low pressure, especially if the problem developed suddenly, the pressure regulator may be worth having inspected.
A plumber can test the system and determine whether the regulator is functioning properly.
6. Problems With Your Water Main
The water main supplies water from the municipal system to your home.
If there's a problem with the service line or water main supplying your property, your entire home may experience reduced water pressure.
This is particularly important if:
The pressure is low at every fixture
Your neighbors are experiencing similar problems
The issue appeared suddenly
You've recently had water-main or street work near your home
If your neighbors have normal pressure but yours is significantly lower, your home's plumbing may be the source of the problem.
7. Corroded or Aging Plumbing
The age and condition of your plumbing can have a major impact on water flow.
Certain older pipe materials can corrode internally over time. As corrosion and buildup accumulate, the opening inside the pipe can become increasingly restricted.
The result can be gradually declining water pressure throughout the home.
If your home has older plumbing and you've noticed increasingly poor water flow, it may be time for a professional evaluation.
How to Tell If Low Water Pressure Is a Big Problem
Not every low-pressure problem requires an emergency plumber.
It's probably a simple fixture issue if:
Only one faucet is affected
Cleaning the aerator restores normal flow
The issue is isolated to one fixture
It's worth having a plumber investigate if:
Multiple fixtures have low pressure
The problem affects the entire house
The pressure suddenly drops
You notice signs of a leak
Your water bill has unexpectedly increased
The problem keeps coming back
The most important thing is to pay attention to whether the problem is isolated or happening throughout your home.
Don't Ignore a Sudden Drop in Water Pressure
Low water pressure can be caused by something as simple as a clogged faucet aerator but it can also be your plumbing system's way of telling you there's a bigger problem.
If you've checked the simple possibilities and your water pressure is still low, it's worth getting to the root of the problem rather than simply living with it.
On Demand Plumbing can help diagnose the cause of low water pressure and recommend the right solution for your home.
Don't settle for a trickle when your plumbing should be working properly.