Low Water Pressure Causes

If you've noticed low water pressure at just one faucet or shower, the problem may be right at the fixture.

Over time, minerals, sediment, and other debris can build up inside faucet aerators and showerheads. Mineral deposits are especially common in areas with hard water, and they can gradually restrict the flow of water.

What to look for:

• One faucet or shower has noticeably weaker water flow than others.
• Water sprays unevenly or in different directions.
• The problem develops gradually rather than happening all at once.

What you can do: Try cleaning the faucet aerator or showerhead. Many can be removed and soaked in a suitable descaling solution to help loosen mineral deposits. Follow the manufacturer's instructions, especially for specialty finishes.

If cleaning the fixture doesn't improve the flow, or several fixtures are affected, there may be another issue within the plumbing system.

Your home's water supply passes through valves that control the flow of water into the plumbing system. If one of these valves is partially closed, it can restrict water flow throughout the house.

This can happen after plumbing work, repairs, or maintenance. Sometimes a valve simply wasn't fully reopened after the work was completed.

What to look for:

• Water pressure is low throughout the home.
• The problem started after plumbing repairs or work on the water supply.
• A main shutoff valve or water meter valve may not be fully open.

What you can do: If you're comfortable doing so, check whether your home's main water shutoff valve is fully open. Avoid forcing a stiff, corroded, or damaged valve, as it could break or begin leaking.

If the valve is fully open and the pressure is still low, a plumber can check the supply valves and other components to determine what's restricting the flow.

Some homes have a pressure-reducing valve, also called a pressure regulator, that helps control incoming water pressure and keep it within an appropriate range for the home's plumbing system.

When a pressure regulator begins to fail, it may no longer maintain the proper pressure. Depending on the type of failure, water pressure can become too low, too high, or fluctuate.

What to look for:

• Water pressure has gradually decreased throughout the house.
• Pressure changes unexpectedly or fluctuates.
• Adjusting or cleaning individual fixtures doesn't solve the problem.

A plumber can test the home's water pressure with a gauge and determine whether the regulator is working properly.

A faulty regulator may need to be adjusted or replaced. Because water pressure that's too high can also damage plumbing fixtures and appliances, it's important to have the system checked rather than simply trying to increase the pressure yourself.

Your home's plumbing pipes carry water every day, but their condition can change over time.

Mineral deposits can accumulate inside pipes, while older metal pipes may develop corrosion. Both can restrict the space available for water to flow through, reducing the amount of water that reaches your fixtures.

This is more likely to be an issue in older plumbing systems, although mineral buildup can affect plumbing components in newer homes, too.

What to look for:

• Water pressure has gradually declined over months or years.
• Multiple faucets or fixtures have reduced flow.
• Older galvanized steel pipes are present in the home.
• Discolored water or other changes in water quality accompany the pressure problem.

If the restriction is inside the plumbing system, cleaning a faucet aerator won't solve the underlying issue. A plumber can inspect the pipes, evaluate the condition of the system, and determine whether a repair or pipe replacement is appropriate.

A leak somewhere in your plumbing system can reduce the amount of water available to your fixtures. If a water line is damaged or leaking, you may notice a change in pressure, particularly if the leak is substantial.

Not every leak causes low water pressure, and small leaks may not affect pressure at all. However, a sudden change in water pressure combined with other warning signs is worth investigating.

What to look for:

• An unexplained increase in your water bill.
• Wet spots in the yard or unusually soggy areas of the lawn.
• Damp walls, ceilings, or flooring.
• The sound of running water when all faucets and water-using appliances are turned off.

If you suspect a leak, don't ignore it. Water leaks can cause property damage and may worsen over time.

If you can safely access your home's water meter, you can check whether it continues to register water use when everything is turned off. Keep in mind that appliances, irrigation systems, and other automatic water use can affect the reading.

If you suspect a hidden leak, a plumber can help locate the source and recommend the appropriate repair.

Sometimes, low water pressure has nothing to do with the plumbing inside your home.

Water pressure can be affected by work on municipal water lines, water main breaks, maintenance, or other issues with the public water supply. If several homes in your neighborhood are experiencing the same problem, the source may be outside your property.

What to look for:

• Neighbors are experiencing similar pressure problems.
• The pressure dropped suddenly.
• You recently received a notice about water system maintenance or construction.

Before scheduling a plumbing repair, check with your local water provider to see whether there is a known service issue in your area.

If the municipal supply is operating normally and your home continues to have low pressure, a plumber can investigate whether the issue is related to your service line, shutoff valves, or interior plumbing.

For homes that rely on a private well, low water pressure may be related to the well pump, pressure tank, pressure switch, or other parts of the water supply system.

A well system uses these components to deliver water and maintain pressure throughout the home. If one of them isn't working correctly, you may notice reduced flow or fluctuating pressure.

What to look for:

• Water pressure rises and falls while using water.
• Pressure is low at several fixtures.
• The well pump runs more frequently than usual or seems to run continuously.
• The problem started after a power outage or an issue with the well system.

Well systems have specialized components, so it's important to have the system evaluated by a qualified well or pump professional when the problem appears to be related to the well itself.

If the well is supplying water normally but pressure is low inside the house, a plumber may be able to help identify an issue with the home's plumbing or pressure equipment.