Start with the pressure regulator and main shutoff valve

Low water pressure usually comes from one of three places: a faulty pressure regulator, a partially closed main shutoff valve, or mineral buildup in your pipes. The fastest fix is to check whether someone has accidentally closed your main shutoff valve — it's typically located where the water line enters your home, often in the basement, crawl space, or outside near the foundation. Turn the handle counterclockwise (or pull it out if it's a ball valve) to make sure it's fully open.

Next, locate your pressure regulator if you have one — it's a bell-shaped or cylindrical device on the main water line, usually within a few feet of the shutoff valve. Most homes have one. If the adjustment screw on top is loose or turned all the way down, that's your culprit. Turn it clockwise to increase pressure, but stop when you reach 80 pounds per square inch (psi). Most homes run between 50 and 80 psi; anything above 80 can damage pipes and appliances over time.

Key Takeaways

  • Check your main shutoff valve first — it may be partially closed, which is the simplest reason for low pressure and the easiest to fix.
  • If you have a pressure regulator, turning its adjustment screw clockwise increases pressure, but do not exceed 80 psi or you risk damaging your plumbing.
  • Mineral deposits in aerators and showerheads can block water flow; unscrew them, soak them in vinegar, and clean out the sediment.
  • If pressure is low at only one fixture, the problem is local to that fixture; if it's low everywhere, the issue is in your main line or regulator.
  • A failing pressure regulator or a leak in the main line requires a licensed plumber to diagnose and repair safely.

Clean aerators and showerheads to remove mineral buildup

Mineral deposits from hard water clog the small screens inside faucet aerators and showerheads. This is especially common in areas with hard water. Unscrew the aerator from the end of your kitchen or bathroom faucet — it usually comes off by hand, though you may need a wrench if it's stuck. Soak it in a bowl of white vinegar for 30 minutes to an hour, then use an old toothbrush to scrub away the white or tan mineral crust.

Rinse it thoroughly under running water and screw it back on. Do the same with showerheads. If you have low pressure at only one or two fixtures, cleaning the aerators will often restore it completely. If pressure is low everywhere in your home, the blockage is deeper in your pipes and cleaning individual fixtures won't help.

Identify whether the problem is everywhere or just one fixture

Before you call a plumber or buy new equipment, turn on the cold water at your kitchen sink, then check the pressure at a bathroom sink, shower, and outdoor hose. If pressure is normal at some fixtures and low at others, you have a local problem — usually a clogged aerator, a failing valve under that specific sink, or a leak in the line serving that fixture.

If pressure is low everywhere, the issue is in your main water line, your pressure regulator, or your shutoff valve. This is when you need to check the regulator adjustment and the shutoff position first. If both are correct and pressure is still low, you likely have a leak in the main line or a regulator that has failed internally.

Check for leaks in your main water line

A leak in the main water line between the street and your home will reduce pressure throughout the house. To check for a leak, turn off all water-using appliances and fixtures, then look at your water meter. If the meter is still moving, water is leaking somewhere underground. You can also watch your water bill — a sudden spike with no change in usage is a sign of a leak.

If you suspect a leak, call your water utility first. Many utilities will check the meter and the line from the street to your home at no charge. If the leak is on your property (between the meter and your house), you will need a licensed plumber to locate and repair it. This is not a DIY job — main line leaks require digging and specialized equipment.

Replace a failing pressure regulator

If your pressure regulator is more than 10 to 15 years old, or if adjusting the screw doesn't increase pressure, the regulator has likely failed internally. A regulator that no longer responds to adjustment needs to be replaced. This is a job for a licensed plumber — the regulator is under pressure and requires proper tools and knowledge to remove and install safely.

A plumber will shut off the main water, unscrew the old regulator, and install a new one set to your preferred pressure (usually 60 to 70 psi for most homes). The cost varies by region and plumber, but replacement is typically less expensive than the cost of water damage from a failed regulator that lets pressure spike.

Consider a whole-house water pressure booster pump

If your water pressure is consistently low even after checking the regulator and main valve, and your water utility confirms there is no leak, your home may be in a low-pressure area of the water system. Some homes are at the end of a long main line or at a higher elevation, which naturally reduces pressure. In these cases, a pressure booster pump can help.

A booster pump is a small electric pump installed on your main water line that increases pressure throughout your home. Installation requires a plumber and costs more than regulator adjustment, but it's a permanent solution if low pressure is a chronic problem. The pump runs automatically when you use water and shuts off when you don't, so it doesn't waste energy.

Know when to call a plumber

Call a licensed plumber if adjusting the pressure regulator doesn't work, if you suspect a leak in the main line, if pressure is low at only one fixture and cleaning the aerator didn't help, or if your regulator is very old and not responding to adjustment. A plumber can measure your actual water pressure with a gauge, locate leaks, and diagnose whether the problem is in your home or in the water utility's line.

Do not attempt to replace a pressure regulator yourself unless you have plumbing experience — the main water line is under pressure and mistakes can cause leaks or water damage. A plumber's visit costs less than the damage a failed DIY repair can cause.

Frequently Asked Questions

What is normal water pressure for a home?

Most homes run between 50 and 80 psi. Anything below 40 psi feels noticeably weak, and anything above 80 psi can damage pipes, water heaters, and appliances over time. If you're unsure, a plumber can measure your pressure with a straightforward gauge.

Can I adjust the pressure regulator myself?

Yes, if you can locate it and it has an adjustment screw on top. Turn the screw clockwise to increase pressure, but do not exceed 80 psi. If the regulator doesn't respond to adjustment or you're unsure how to find it, call a plumber.

Why is my water pressure low in just the shower?

The showerhead aerator is usually clogged with mineral deposits. Unscrew it, soak it in vinegar for 30 minutes, scrub it with a toothbrush, and reinstall it. If that doesn't work, the valve under the sink serving that line may be partially closed or failing.

How much does it cost to fix low water pressure?

Costs vary by region and the cause. Cleaning aerators is free. Adjusting a regulator may cost $100 to $200 if a plumber does it. Replacing a regulator typically runs $300 to $500. A booster pump installation can cost $1,000 to $3,000 depending on your system.

Will low water pressure affect my water heater?

Low pressure won't damage a water heater, but it will make hot water take longer to reach your fixtures. If pressure is very low, some tankless water heaters may not set up at all. A plumber can advise whether your heater is affected.