Check Your Main Water Shut-Off Valve First

The fastest fix for low water pressure is often a partially closed shut-off valve. This valve sits where the water line enters your house from the street — usually in the basement, crawl space, or under the kitchen sink. If someone turned it halfway closed during a repair or by accident, your whole house loses pressure.

Turn the valve handle counterclockwise until it stops. If the handle is a lever, point it in line with the pipe. You should feel resistance but not have to force it. If the valve was partially closed, you may hear water rush through the pipes as pressure returns. This takes seconds and costs nothing.

If the valve is already fully open and pressure is still low, move to the next step. A stuck or corroded valve that will not turn smoothly may need replacement by a plumber, but that is less common than a valve someone closed without realizing.

Key Takeaways

  • A partially closed main shut-off valve is the most common cause of low pressure in the whole house and takes seconds to fix.
  • Sediment buildup in your water heater or pipes reduces pressure over time and can be flushed out without replacing equipment.
  • A faulty pressure regulator (if your house has one) can be adjusted or replaced to restore normal pressure.
  • Low pressure from the street is a utility problem, not yours — contact your water company to report it and ask whether other homes nearby are affected.

Flush Sediment from Your Water Heater

Mineral deposits and sediment collect at the bottom of your water heater over years of use. This buildup narrows the pipes inside the tank and slows the flow of hot water. If only your hot water pressure is low, flushing the heater often restores it.

Turn off the heater's power (switch the breaker to off for electric, or turn the gas knob to pilot 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 — water will be hot — and let it run until the water runs clear. This usually takes 15 to 30 minutes. Close the valve, remove the hose, turn the power back on, and wait for the tank to refill.

If you are not comfortable doing this yourself, a plumber can flush the heater for you in under an hour. The cost is usually between $100 and $200, depending on your area and tank size.

Clean or Replace Your Pressure Regulator

Many homes have a pressure regulator — a bell-shaped device on the main water line that keeps pressure from getting too high and damaging pipes. If this regulator fails or gets clogged with sediment, it can restrict flow and lower pressure throughout the house.

The regulator sits near the main shut-off valve. Look for a brass or metal dome with an adjustment screw on top. If you have one and pressure is low everywhere, the regulator may be the problem. You can try adjusting it by turning the screw clockwise a quarter turn, then checking pressure at a faucet. Do not turn it more than a half turn — too much pressure damages pipes and fixtures.

If adjustment does not help, the regulator likely needs replacement. This is a job for a plumber because it requires shutting off water, draining the line, and installing a new regulator. The part costs $50 to $150, and labor usually runs $150 to $300.

Look for Leaks in Your Pipes

A hidden leak in your supply lines can reduce pressure throughout the house or in one section of it. Check under sinks, in the basement, and in crawl spaces for wet spots, water stains, or the sound of running water when no faucets are on.

If you find a leak, you have two options. A small pinhole leak in copper pipe can sometimes be patched temporarily with epoxy putty or a pipe clamp from a hardware store — this buys time but is not permanent. A larger leak or a leak in a joint usually requires the section of pipe to be cut out and replaced, which is a plumber's job.

Even a small leak wastes water and lowers pressure. If you suspect a leak but cannot find it, a plumber can use a pressure test to locate it. This involves isolating sections of pipe and measuring pressure drop, which takes an hour or two and costs $150 to $300.

Check Whether the Problem Is Only at One Faucet

If pressure is low at only one sink, shower, or toilet, the problem is local to that fixture, not your whole system. Start by removing the aerator — the screen at the tip of the faucet — and rinsing it under running water to clear sediment. Screw it back on and test. This fixes the problem in many cases.

If pressure is still low after cleaning the aerator, the shutoff valve under that sink may be partially closed. Turn it counterclockwise until it stops. If that does not work, the valve itself may be stuck or corroded and need replacement — a plumber can do this in 30 minutes for $100 to $200.

For a shower, you may be able to clean the showerhead the same way: unscrew it, soak it in vinegar for an hour to dissolve mineral deposits, and rinse it. If pressure remains low, the valve behind the wall may need attention from a plumber.

Contact Your Water Company if Pressure Is Low from the Street

If you have checked your shut-off valve, flushed your heater, and found no leaks, the problem may be on the utility side. Low pressure can result from main breaks, hydrant flushing, or high demand in your area during peak hours.

Call your water company's customer service line and report low pressure. They can check whether the problem is widespread in your neighborhood or isolated to your meter. If it is widespread, they are already working on it. If it is only your house, they may send someone to check the meter and the line from the street to your home.

The water company does this work at no charge to you. If they find a problem on their side of the meter, they fix it. If the problem is on your side, they will tell you and you can hire a plumber.

Consider a Whole-House Pressure Booster Pump

If your water company confirms that street pressure is straightforward low in your area — common in rural locations or on hills — a pressure booster pump can raise it. These devices sit on your main water line and use a motor to push water through your house at higher pressure.

A basic booster pump costs $300 to $800 for the unit itself, plus $500 to $1,500 for installation by a plumber. The pump runs on electricity and adds a small amount to your power bill. It is a permanent solution if low pressure is a chronic problem in your area, but it is not worth installing if the pressure issue is temporary or caused by something else in your house.

Before buying a booster pump, have a plumber measure your actual water pressure with a gauge. Normal household pressure is 40 to 60 pounds per square inch (PSI). If yours is below 30 PSI and the water company says that is normal for your area, a booster pump makes sense.

Frequently Asked Questions

Why is my water pressure low only in the morning?

Morning low pressure often happens because the water company is flushing hydrants or doing maintenance early in the day. It usually returns to normal by mid-morning. If it happens every morning, call your water company to ask about their maintenance schedule. If it is not their work, sediment in your heater may be settling overnight and restricting flow until the heater warms up.

Can a water softener cause low pressure?

Yes. Water softeners have filters that can clog with sediment over time. If pressure dropped after you installed one, check whether the filter needs cleaning or replacement. The manual that came with your softener explains how to do this. If the softener is old, it may need a new filter cartridge, which costs $50 to $150.

What PSI should my water pressure be?

Normal household water pressure is 40 to 60 PSI. You can measure yours with a pressure gauge, which costs $10 to $20 at a hardware store and screws onto any outdoor faucet. If your pressure is below 40 PSI, the steps in this guide should help. If it is above 80 PSI, you may need a pressure regulator to protect your pipes.

Does cold weather affect water pressure?

Yes, but usually only if pipes are frozen. If pressure drops during a cold snap, check whether any pipes are visibly frozen or burst. Thaw frozen pipes slowly with a heat lamp or hair dryer — never use a torch. If a pipe has burst, you need a plumber right away to prevent water damage.

How much does it cost to hire a plumber to fix low water pressure?

A service call to diagnose the problem usually costs $100 to $200. If the fix is straightforward — like adjusting a valve or cleaning an aerator — the plumber may do it during that visit at no extra charge. If you need a new regulator, valve, or pipe section, add $150 to $500 for parts and labor depending on what is wrong.