Start by finding where the pressure drop happens

Low water pressure throughout your whole house points to a problem before the water reaches your pipes — usually a closed valve, a clogged meter, or an issue with your water line from the street. Low pressure in only one room or one fixture means the problem is in that branch of your plumbing or in the fixture itself.

Check your main water shut-off valve first. It is typically located where the water line enters your house, often in the basement, crawl space, or near the foundation. The valve handle should point in the same direction as the pipe — if it is perpendicular to the pipe, it is partially or fully closed. Turn it to align with the pipe direction and test your pressure. If that fixes it, you have found your problem. If not, move to the next step.

If you have a water meter, look for a second shut-off valve between the meter and your house. This valve can get stuck or partially closed over time. Try turning it fully open as well. Some homes also have a pressure regulator — a bell-shaped device near the main shut-off — that can fail and reduce pressure throughout the house.

Key Takeaways

  • A closed main shut-off valve or meter valve is the fastest fix and costs nothing to check.
  • Sediment buildup in aerators and screens is the most common cause of low pressure in a single faucet or fixture.
  • A failing pressure regulator affects the whole house and usually requires replacement by a plumber.
  • Mineral deposits in old pipes can reduce pressure gradually over years and may require professional flushing or pipe replacement.
  • If pressure is low only in hot water, the problem is usually in your water heater or its shut-off valve.

Clean aerators and screens on individual faucets

If only one sink, shower, or faucet has low pressure, the aerator — the screen at the tip of the faucet — is usually clogged with sediment or mineral deposits. Unscrew the aerator by hand or with a wrench, depending on how tight it is. Rinse it under running water and use an old toothbrush to scrub away any visible buildup.

If the aerator is heavily caked with mineral deposits, soak it in white vinegar for 30 minutes to an hour, then scrub again. Reassemble it and test the pressure. For shower heads, the same method works — unscrew the head, clean the screen, and soak in vinegar if needed. If the aerator is cracked or damaged, replace it with a new one from any hardware store for a few dollars.

Toilet fill valves and washing machine inlet screens can also clog. For a toilet, turn off the water at the shut-off valve behind the tank, flush to empty it, then disconnect the water line and clean the screen inside the connection. For a washing machine, turn off both hot and cold shut-off valves, disconnect the inlet hoses, and clean the small screens inside the hose connections.

Check for leaks in your water line

A leak between your meter and your house reduces pressure and wastes water. Look for wet spots in your yard, foundation cracks with water seeping through, or unusually green patches of grass. If you suspect a leak but cannot see one, turn off all water inside your house, then check whether your meter is still running — if it is, water is leaking somewhere underground.

Underground leaks require a plumber to locate and repair, as they involve digging and replacing sections of pipe. This is not a repair you can do yourself. Call a licensed plumber and describe what you have observed. They can use acoustic listening equipment to pinpoint the leak location.

Flush your water heater if only hot water pressure is low

If cold water pressure is normal but hot water pressure is weak, the problem is usually sediment buildup inside your water heater tank. Over time, minerals settle at the bottom and can clog the outlet. Turn off the power to your water heater (or the gas valve if you have a gas heater), turn off the cold water inlet valve at the top of the tank, and attach a garden hose to the drain valve at the bottom. Run the hose to a floor drain or outside and open the valve to drain several gallons of water.

Watch the water that comes out — if it is cloudy or brown, sediment is present. Close the drain valve, turn the inlet valve back on, and repeat the process until the water runs clear. This usually takes 15 to 30 minutes. Turn the power or gas back on and test your hot water pressure.

If flushing does not help, the shut-off valve on the cold water inlet to your heater may be partially closed or clogged. Check that it is fully open and in line with the pipe. If it is stuck, a plumber can replace it.

Test and replace your pressure regulator

A pressure regulator is a bell-shaped or cylindrical device installed on your main water line, usually near the shut-off valve. It keeps water pressure from getting too high and damaging your pipes. If it fails, pressure drops throughout your house. You can test it by attaching a pressure gauge to an outdoor faucet or a laundry sink. Normal household water pressure is 40 to 80 pounds per square inch (PSI). If your gauge reads below 40 PSI and your shut-off valves are fully open, the regulator may be failing.

Replacing a pressure regulator requires turning off the main water valve, unscrewing the old regulator, and screwing in a new one. This is a straightforward job if you are comfortable with basic plumbing, but if you are not, a plumber can do it in under an hour. Regulators cost between $50 and $150 depending on the brand and size.

Know when to call a plumber

If you have checked the main shut-off valve, cleaned aerators, and tested your pressure regulator and pressure is still low, the problem is likely inside your pipes — either mineral buildup in old galvanized pipes, a partially collapsed pipe, or a leak you cannot see. These problems require professional diagnosis and repair.

A plumber can use a camera to inspect the inside of your pipes, perform a pressure test to confirm the problem, and recommend whether flushing, pipe replacement, or another solution is needed. If your home has galvanized steel pipes installed more than 50 years ago, mineral deposits inside the pipes are common and may require replacing sections of pipe or the entire system.

Frequently Asked Questions

Why is my water pressure low only in the morning?

Low pressure in the morning often means your water heater is draining slowly or your hot water line has a leak that develops overnight. Run only cold water for a few minutes — if pressure returns to normal, the problem is in your hot water system. If cold water pressure is also low, check whether your water company does maintenance early in the morning in your area.

Can I increase my water pressure if it is naturally low in my area?

If your water company delivers water at low pressure, you can install a pressure booster pump on your main water line. This device uses a small electric pump to increase pressure throughout your house. A plumber can install one, and the cost is typically $300 to $800 depending on the pump size and your home's layout.

What does it mean if pressure is high in some rooms and low in others?

Uneven pressure usually means one branch of your plumbing has a clog or partially closed valve. Check the shut-off valve for that room or fixture — it may be partially closed. If the valve is fully open, sediment may be blocking that line, and a plumber can flush it or replace that section of pipe.

Is low water pressure a sign of a serious plumbing problem?

Low pressure is sometimes just a clogged aerator, but it can also signal a leak, a failing regulator, or pipe corrosion. If you cannot find the cause after checking valves and aerators, have a plumber inspect your system. Catching a leak or pipe problem early is cheaper than waiting for water damage.