Start with the water meter and main shutoff valve

Low water pressure usually comes from one of three places: a partially closed valve, a clogged pipe, or a problem at the street. Before you call a plumber, check the two valves you can control yourself. The main water shutoff valve is typically near where the water line enters your house—often in the basement, crawl space, or under the kitchen sink. It should be fully open. If it is a ball valve (a lever handle), it should point in line with the pipe. If it is a gate valve (a round handle), turn it counterclockwise until it stops, then back it up a quarter turn so it does not stick.

Next, locate your water meter, usually in the same area or outside near the street. Beside or just after the meter is a second shutoff valve. Check that this one is also fully open using the same method. If either valve was partially closed, open it fully and test your pressure at a sink faucet. Many cases of low pressure are solved at this step.

If both valves are open and pressure is still low, the problem is either inside your pipes or upstream at the street. You can narrow this down by calling your water company and asking whether they have reported low pressure in your area recently. If they have not, the issue is in your house.

Key Takeaways

  • Check your main shutoff valve and the valve at your water meter first—both should be fully open, and closing either one is the most common cause of low pressure.
  • If pressure is low at only one faucet, the problem is usually a clogged aerator or a mineral buildup inside that fixture, which you can clean in minutes.
  • If pressure is low throughout the house, you likely have mineral deposits in your pipes or a leak somewhere, and you may need a plumber to locate and fix it.
  • Installing a pressure regulator or booster pump can raise pressure if your water company delivers it below 60 pounds per square inch, but this is a job for a licensed plumber.
  • Sediment in your water heater tank reduces pressure on the hot side only—draining the tank once a year prevents this and extends the heater's life.

Test pressure at different faucets to find where the problem is

Low pressure in one bathroom but not another tells you the problem is local to that fixture. Low pressure everywhere means the problem is in your main line or at the meter. Test at least three faucets—one in the kitchen, one in a bathroom sink, and one in a shower—and note which ones are slow.

If only one faucet is weak, unscrew the aerator (the screen at the tip of the faucet) by hand or with a wrench. Rinse it under running water and use an old toothbrush to scrub away any mineral buildup. If your water is hard, soak the aerator in white vinegar for an hour first. Screw it back on and test. This fixes most single-faucet problems in under five minutes.

If the shower head is the only weak one, remove it the same way and clean it. Shower heads often have small holes that clog with mineral deposits, especially in hard-water areas. If cleaning does not work, a new aerator or shower head costs five to twenty dollars and takes thirty seconds to install.

Drain your water heater if hot water pressure is low but cold is normal

If cold water pressure is fine but hot water comes out slowly, sediment has built up inside your water heater tank. This is normal after a few years and is straightforward to fix. Turn off the power to the heater (switch off the breaker for electric, or turn the gas valve to pilot for gas). Let the water cool for at least an hour.

Attach a garden hose to the drain valve at the bottom of the tank and run it to a floor drain or outside. Open the drain valve slowly—the water will be hot at first. Let the tank drain completely, which takes twenty to forty minutes. Once it is empty, close the drain valve, turn the power back on, and refill the tank by opening the cold water inlet valve. Test your hot water pressure after ten minutes.

Do this once a year to prevent sediment buildup and to extend your water heater's life by several years. If you are not comfortable doing this yourself, a plumber can do it in under an hour for a service call fee.

Look for leaks if pressure drops suddenly or unevenly

A sudden drop in pressure, or pressure that is low in some rooms but not others, can mean a leak in your pipes. Check your water meter: turn off all faucets and appliances, wait five minutes, and look at the meter again. If the number has changed, water is leaking somewhere.

Small leaks inside walls or under floors are hard to find without equipment. If you suspect a leak, call a plumber who has a leak detection service—they use acoustic equipment or dye to pinpoint the location without tearing into walls. Fixing a leak early prevents water damage and stops you from paying for water you are not using.

If you see water pooling under the house, around the foundation, or in the yard, that is a sign of a major leak. Call a plumber right away. Do not ignore this—water damage gets worse and more expensive to repair the longer it sits.

Install a pressure regulator if your water company delivers pressure that is too high or too low

Water companies deliver pressure between 40 and 80 pounds per square inch (PSI). Most homes work best at 60 to 70 PSI. If your pressure is consistently below 40 PSI, a pressure booster pump can raise it. If it is above 80 PSI, a pressure regulator can lower it and protect your pipes and appliances from damage.

You can check your pressure with an inexpensive gauge (ten to twenty dollars) that screws onto any outdoor faucet. If the reading is outside the normal range, call a licensed plumber. Installing a booster pump or regulator requires connecting it to your main line, which is a job that needs a permit and a professional in most places. The cost ranges from three hundred to eight hundred dollars depending on the type and your location.

Before you invest in a booster pump, confirm with your water company that they are delivering low pressure. Sometimes the problem is a clogged meter or a partially closed valve, which costs nothing to fix.

Replace old galvanized pipes if pressure is low throughout the house and nothing else works

Homes built before 1980 often have galvanized steel pipes, which rust from the inside over time. Rust buildup narrows the pipe and reduces pressure. If your house is old, pressure has always been low, and you have ruled out valves, leaks, and aerators, galvanized pipes are likely the cause.

Replacing all the pipes in a house is a major job that costs several thousand dollars, depending on the size of your house and how straightforward the pipes are to reach. A plumber can run a camera through your pipes to confirm rust buildup before you commit to replacement. Some people choose to replace only the main line from the meter to the house, which is cheaper and improves pressure somewhat.

If you are not ready for a full replacement, a booster pump (described above) can raise pressure enough to make showers and washing machines work better. This is a temporary solution, but it buys time if you are planning to replace the pipes later.

Frequently Asked Questions

How do I know if my water pressure is actually low?

Normal household pressure is 60 to 70 PSI. You can measure it with a pressure gauge (ten to twenty dollars) that screws onto an outdoor faucet. If you do not want to buy a gauge, call a plumber for a free pressure check, or ask your water company to test the pressure at the meter. Pressure below 40 PSI will make showers weak and washing machines fill slowly.

Can low water pressure damage my appliances?

Low pressure does not damage appliances, but it makes them work poorly—dishwashers and washing machines may not fill properly, and water heaters may not heat efficiently. High pressure above 80 PSI can damage pipes, water heaters, and valves over time, which is why a regulator is worth installing if your pressure is consistently high.

Why is my hot water pressure low but cold water is fine?

Sediment in your water heater tank is the most common cause. Drain the tank as described above. If that does not work, the mixing valve inside the heater may be failing, and you will need a plumber to replace it. This usually costs one hundred to three hundred dollars.

Should I call a plumber or try to fix low pressure myself?

Start with the free checks: open your main shutoff valve and meter valve, clean aerators, and drain your water heater. If pressure is still low throughout the house, call a plumber. They have tools to detect leaks and test pressure accurately, and they can tell you whether the problem is in your house or at the street.

Does a water softener improve pressure?

No. A water softener removes minerals that cause hard water, but it does not raise pressure. If you have hard water and low pressure, you have two separate problems. Clean your aerators and test your pressure first, then decide whether a water softener is worth the cost for other reasons.