Check Your Main Water Shut-Off Valve First

The fastest fix for low water pressure is often a partially closed valve you did not know was there. Your main water shut-off valve — the one that controls water flow into your entire house — has a handle that can be turned to restrict flow. If someone closed it partway during a repair or emergency, your pressure drops when ready.

Find this valve where the water line enters your house, usually in the basement, crawl space, or near the foundation on the street-facing side. The handle should point in the same direction as the pipe (parallel to it). If it points across the pipe (perpendicular), it is partially closed. Turn it slowly until it points parallel to the pipe. Do this gradually — turning it too fast can create a pressure spike that damages fixtures.

If the valve is already pointing the right direction, move to the next step. If you turned it and pressure improved, you are done. If pressure is still low after adjusting it fully open, the valve itself may be stuck or failing internally, and you will need a plumber to replace it.

Key Takeaways

  • Your main shut-off valve can restrict water pressure if it is partially closed — check that the handle points parallel to the pipe.
  • A pressure regulator that is set too low will reduce pressure throughout your house and can be adjusted or replaced by a plumber.
  • Mineral buildup in aerators and showerheads is the most common cause of low pressure in one fixture, and cleaning or replacing them takes minutes.
  • If only one fixture has low pressure, the problem is almost always that fixture itself, not your main line or pressure system.
  • Water pressure above 80 pounds per square inch can damage pipes and fixtures, so do not increase pressure beyond what your system needs.

Look for a Pressure Regulator and Check Its Setting

Many houses have a pressure regulator — a bell-shaped or cylindrical device screwed onto the main water line, usually near the shut-off valve. This device reduces incoming pressure to a safe level for your home's pipes and fixtures. If it is set too low, your entire house will have weak pressure.

A pressure regulator has an adjustment screw on top. Turning it clockwise increases pressure; counterclockwise decreases it. Before you adjust anything, measure your current pressure with an inexpensive pressure gauge (available at any hardware store for $10 to $20). Screw it onto an outdoor faucet or a laundry sink faucet. Normal household pressure is 40 to 60 pounds per square inch (psi). If your gauge reads below 40 psi, the regulator may be set too low.

Turn the adjustment screw clockwise a quarter-turn and retest. Repeat until you reach 50 to 60 psi. Do not exceed 80 psi — higher pressure damages pipes, water heaters, and appliances. If the regulator will not increase pressure no matter how far you turn the screw, it has failed internally and needs replacement by a plumber.

Clean or Replace Aerators and Showerheads

If only one faucet or showerhead has low pressure, the problem is almost always mineral buildup inside that fixture, not your main water line. Aerators — the small screens at the tip of faucets — trap sediment and minerals over time. Showerheads clog the same way.

Unscrew the aerator by hand (turn counterclockwise). If it is stuck, wrap a cloth around it and use pliers. Rinse it under hot water and use an old toothbrush to scrub away white or tan mineral deposits. If deposits are heavy, soak the aerator in white vinegar for 30 minutes, then scrub again. Screw it back on and test the pressure.

For showerheads, unscrew the entire head from the arm. Soak it in a plastic bag filled with white vinegar — use a rubber band to hold the bag in place — for two to four hours. Scrub the holes with a toothbrush or a thin wire. Rinse thoroughly and screw it back on. If cleaning does not restore pressure, replace the aerator or showerhead with a new one (they cost $5 to $15).

Check for Leaks in Your Visible Pipes

A leak in your main water line or supply pipes will reduce pressure throughout your house. Walk your basement, crawl space, or any area where pipes are visible. Look for water dripping, pooling, or staining on pipes or the surrounding area. Even a small leak can lower pressure noticeably.

If you find a leak on a visible section of pipe, you can temporarily slow it with plumber's tape or epoxy putty (available at hardware stores), but a plumber will need to replace the damaged section. If you suspect a leak in a wall or underground, you may notice soft spots in your floor, unusually high water bills, or a constant hissing sound near the water meter. These signs warrant a call to a plumber, who can use specialized equipment to locate hidden leaks.

Flush Your Water Heater

Sediment buildup inside your water heater reduces the flow of hot water and can affect overall pressure. If you have noticed low pressure only on the hot side, or if your water heater is more than five years old and has never been flushed, sediment is likely the cause.

Turn off the power to your water heater (switch off the breaker for electric, or the gas valve for gas). 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 and let water run until it runs clear — this usually takes 15 to 30 minutes. Close the valve, remove the hose, and turn the power back on. Test your hot water pressure after the tank refills (this takes 30 to 60 minutes).

If you are not comfortable doing this yourself, a plumber can flush the tank for $100 to $200. Flushing every one to two years prevents sediment from accumulating.

Consider Your Water Meter or Supply Line

If pressure is low throughout your house and the shut-off valve and regulator are both set correctly, the problem may be your water meter or the supply line from the street. Water meters can become clogged with sediment, and old supply lines can develop internal corrosion that restricts flow.

You cannot adjust or clean a water meter yourself — that is the water company's responsibility. Contact your local water utility and report low pressure. They will send someone to inspect the meter and supply line at no charge. If the meter is the problem, they will replace it. If the supply line is corroded, they may replace it or recommend that you hire a plumber to replace the section on your property.

Know When to Call a Plumber

Call a plumber if pressure remains low after you have checked the shut-off valve, adjusted the regulator, cleaned aerators, and looked for visible leaks. A plumber can test your system with specialized equipment, identify whether the problem is in your main line or a specific fixture, and determine whether the issue is a failed regulator, a hidden leak, or corrosion in your pipes.

Expect a service call to cost $100 to $200 for diagnosis. Repairs vary widely — replacing a regulator costs $200 to $400, while replacing corroded supply lines can cost $1,000 or more depending on how much pipe needs to be replaced. Getting a diagnosis first will tell you whether the repair is worth the cost or whether you should focus on managing pressure with individual fixture upgrades.

Frequently Asked Questions

Can I increase water pressure above 80 psi?

You can, but you should not. Pressure above 80 psi damages water heaters, washing machines, dishwashers, and pipes. It also causes leaks to develop faster and shortens the life of fixtures. If your regulator is set above 80 psi, lower it to 60 to 70 psi for the best balance of pressure and equipment longevity.

Why is my water pressure low only in the morning?

Morning low pressure often happens because water has been sitting in your pipes overnight and minerals have settled. Run a faucet for 30 seconds to a minute to flush the line. If pressure returns to normal, this is not a problem. If it stays low, the issue is your main system, not the time of day.

Does a water pressure booster pump really work?

Yes, but only if your incoming pressure is at least 20 psi. A booster pump takes whatever pressure you have and increases it. If your main line pressure is below 20 psi, the pump cannot do much. A plumber can test your incoming pressure and tell you whether a booster pump will help. They cost $300 to $800 installed.

What is the difference between low pressure and low flow?

Low pressure means weak force when you turn on a faucet — water comes out slowly even though the valve is fully open. Low flow means less total water volume, but the water that comes out has normal force. They have different causes: pressure problems usually point to a regulator or valve issue, while flow problems often mean a clogged aerator or meter.

Should I be worried if my water pressure is 70 psi?

No. Pressure between 50 and 70 psi is ideal for most homes. It is strong enough for showers and appliances to work well, but not so high that it damages pipes and fixtures. If you are comfortable with your current pressure, there is no reason to adjust it.