Where to find and adjust your water pressure regulator

The easiest way to lower water pressure is to adjust the pressure regulator, a bell-shaped valve usually located where the main water line enters your house. Look for it near the water meter, in the basement, crawl space, or outside where the line comes in from the street. It has an adjustment screw on top—turning it counterclockwise lowers pressure, clockwise raises it.

If you don't see a regulator, your house may not have one installed. Older homes sometimes lack them, and some municipal water systems deliver water at a lower pressure naturally. If you need to raise pressure and there's no regulator, you'll need a professional to install one or diagnose why pressure is low.

Before you adjust anything, measure your current pressure with a water pressure gauge, a straightforward tool that screws onto any outdoor faucet or hose bib. They cost $10 to $20 at hardware stores. Normal household pressure is 40 to 60 pounds per square inch (psi). Below 40 psi feels weak; above 80 psi can damage fixtures and appliances.

Key Takeaways

  • Your pressure regulator sits where the main water line enters the house and has an adjustment screw on top that you turn by hand or with a wrench.
  • Measure pressure with a gauge screwed onto an outdoor faucet before and after adjusting to confirm the change worked.
  • Turning the screw counterclockwise lowers pressure; clockwise raises it—make small quarter-turn adjustments and wait a few minutes between each one.
  • If you have no regulator and pressure is too high, a plumber can install one; if pressure is too low and there's no regulator, the problem may be in the municipal supply or your home's pipes.
  • High pressure damages water heaters, toilets, and washing machines over time, so lowering it protects your appliances even if the pressure feels normal.

How to make the adjustment safely

Start by turning off the water supply to your house if you're uncomfortable working with the system, though you don't have to—the regulator adjustment itself doesn't require shutting off water. Locate the adjustment screw on top of the regulator and loosen the locknut (the nut below it) with a wrench if it's tight. Some regulators have a plastic adjustment knob instead of a screw.

Make small changes: turn the screw or knob a quarter turn at a time. Wait three to five minutes after each adjustment, then check the pressure gauge again. This prevents overshooting and gives the system time to stabilize. If you're lowering pressure, you may hear water running briefly in the pipes as the system adjusts.

Once you reach the pressure you want, tighten the locknut back down so the adjustment doesn't shift. Check the pressure one more time after a few hours to make sure it held steady. If pressure creeps back up or down, the regulator may be failing and need replacement—call a plumber.

Why high water pressure damages your home

Water pressure above 80 psi puts constant stress on pipes, joints, and appliances. Your water heater, washing machine, dishwasher, and toilet fill valves all wear out faster under high pressure. You may notice leaks at connections, dripping faucets that won't stop, or a water heater that fails years earlier than expected.

High pressure also causes water hammer—a loud banging sound in the pipes when you turn off a faucet quickly. This happens because the fast-moving water slams against the closed valve. Over time, water hammer can crack pipes or loosen connections inside walls, leading to hidden leaks.

Lowering pressure to 50–60 psi protects your fixtures and extends the life of expensive appliances. Even if your pressure feels normal to you, it may still be high enough to cause damage. This is why checking with a gauge is worth the small cost.

When low pressure needs a different fix

If your pressure is below 40 psi and you have a regulator, the regulator itself may be stuck or failing. Try adjusting it upward slightly. If pressure doesn't respond or rises only a little, the regulator needs replacement—a plumber can do this in an hour or two.

If you have no regulator and pressure is low, the problem could be in the municipal water supply (call your water company to check), a partially closed shutoff valve in your home, or mineral buildup inside old pipes. A plumber can test the supply pressure at the meter and trace the issue. Don't install a regulator if the problem is upstream—it won't help.

Low pressure in only one area of the house—like a single bathroom—usually means a clogged aerator on the faucet or a problem with that fixture's supply line, not a system-wide issue. Clean or replace the aerator first before calling for help.

Tools and materials you'll need

A water pressure gauge is essential and costs $10 to $25. An adjustable wrench or socket wrench fits most regulator locknuts. A flathead or Phillips screwdriver may be needed if your regulator has a screw-type adjustment instead of a knob. Most people have these tools already.

You don't need to buy a new regulator unless the existing one fails. Regulators last 10 to 15 years on average, though some fail sooner in areas with very hard water or high mineral content. If you adjust the screw and pressure doesn't change, or if it changes and then drifts back within hours, replacement is likely necessary—a new regulator costs $100 to $300 plus labor.

When to call a plumber

Call a plumber if the regulator adjustment screw won't turn, if you can't locate the regulator, or if pressure changes don't stick. Also call if you have no regulator and pressure is consistently above 80 psi—a plumber can install one and may support it's set correctly.

If you adjust the regulator and pressure still feels weak throughout the house, or if it's high in some areas and low in others, a plumber can test the supply line and identify blockages or leaks. Don't guess at the cause—a quick diagnostic call is cheaper than replacing pipes or appliances damaged by the wrong fix.

Frequently Asked Questions

Can I adjust the regulator myself or do I need a plumber?

You can adjust it yourself with a wrench and a pressure gauge. It's a straightforward quarter-turn adjustment. Call a plumber only if the screw won't budge, the adjustment doesn't work, or you can't find the regulator in your home.

What's the best water pressure for a house?

Aim for 50 to 60 psi. This is strong enough for showers and appliances but low enough to protect pipes and fixtures. Anything above 80 psi will damage things over time, even if it feels fine to you.

How long does it take to adjust water pressure?

The actual adjustment takes five to ten minutes. You'll spend another five to ten minutes measuring pressure before and after to confirm it worked. The whole job is usually done in 15 to 20 minutes.

Will lowering water pressure affect my shower or washing machine?

Lowering pressure from 80+ psi to 50–60 psi will feel slightly weaker, but most people don't notice a real difference in shower flow or washing machine performance. If pressure is already below 60 psi, don't lower it further.

What if my house doesn't have a pressure regulator?

Older homes sometimes lack one. If pressure is high, a plumber can install a regulator—it's a straightforward job. If pressure is low and there's no regulator, the problem is likely in the municipal supply or your home's pipes, and a plumber can diagnose which.