Where to find the water pressure adjustment

The easiest place to raise water pressure is at your main water shut-off valve, which sits where the water line enters your house from the street. This valve usually lives in your basement, crawl space, or utility room near the foundation wall. It may also be in an outdoor box at ground level in your yard. The valve itself is a brass or metal fitting with a handle or knob.

Next to or very close to this main valve, you will find a pressure regulator — a bell-shaped or cylindrical device about the size of a soda can. This regulator controls how hard the water pushes through your pipes. If your home has low water pressure throughout, this is almost always the culprit, and it is the first thing to check.

Some homes do not have a pressure regulator at all, which means your pressure is set by the municipal water system alone. If you cannot find one, your water company controls the pressure from their end, and you would need to contact them to request an increase.

Key Takeaways

  • A pressure regulator near your main water shut-off valve controls how hard water flows through your home, and turning the adjustment screw clockwise raises the pressure.
  • Most regulators have a pressure gauge on top that shows the current pressure in pounds per square inch (psi), and household pressure should stay between 40 and 80 psi.
  • Raising pressure above 80 psi can damage pipes, water heaters, and appliances, so small adjustments of 5 to 10 psi at a time are safer than large jumps.
  • If you cannot find a regulator or the adjustment does not work, low pressure may come from a clogged aerator, a leak, or a problem at the water company, each requiring a different fix.

How to adjust the regulator screw

The pressure regulator has a small adjustment screw on top, usually with a plastic or metal cap. Loosen or remove this cap to expose the screw underneath. Use a wrench or adjustable wrench to turn the screw clockwise — this raises the pressure. Turn it counterclockwise to lower pressure.

Make small adjustments: turn the screw one-quarter turn, then go to a sink or shower and test the pressure. Wait a few seconds for the system to settle. If the pressure still feels low, turn another quarter turn and test again. This slow approach prevents you from overshooting and damaging your pipes or appliances.

Most household water pressure should sit between 40 and 80 pounds per square inch (psi). If your regulator has a pressure gauge on top, you can read the number directly. If it does not have a gauge, you can buy an inexpensive water pressure gauge at any hardware store — screw it onto an outdoor faucet to get a reading.

Why pressure matters and when to stop adjusting

Water pressure that is too high wears out pipes, seals, and appliances faster than normal. A water heater, dishwasher, or washing machine designed for 60 psi will fail sooner if it runs at 90 psi every day. High pressure also causes pipes to bang or rattle when you turn off a faucet, a problem called water hammer.

Pressure below 40 psi feels weak at showers and makes filling a bathtub slow. Pressure above 80 psi is unnecessarily hard on your system. If you have raised the regulator screw and pressure is still below 40 psi, the problem is not the regulator — it is something else, and adjusting further will not help.

When low pressure comes from somewhere else

If you raised the regulator and pressure is still low everywhere in the house, the problem is not the regulator. Check the aerator — the small screen at the tip of your faucet. Unscrew it by hand and rinse it under running water to clear mineral buildup. Screw it back on and test. If pressure improves at that faucet only, mineral deposits were the culprit.

If pressure is low in only one room or one faucet, the problem is local to that line, not your main pressure. This could be a clogged aerator, a partially closed shut-off valve under the sink, or a leak in that branch of pipe. Check the shut-off valve first — it should be fully open (handle parallel to the pipe).

If pressure is low everywhere and the regulator is already set to 60 or 70 psi, you may have a leak somewhere in your system, or the water company may be delivering low pressure to your street. Call your water company and ask them to test the pressure at your meter. They can tell you whether the problem is on their side or yours.

Tools and supplies you will need

To adjust your regulator, you need an adjustable wrench or a wrench that fits the adjustment screw — usually 1/2 inch or 9/16 inch. You may also want a water pressure gauge (about $10 to $20 at a hardware store) to measure pressure before and after your adjustment. A flashlight helps if your shut-off valve is in a dark basement or crawl space.

If you find mineral buildup in an aerator, you may want white vinegar and an old toothbrush to soak and scrub the screen. These are optional — rinsing under water alone usually works.

When to call a plumber

Call a plumber if you cannot find your main shut-off valve or pressure regulator, if the adjustment screw will not turn (it may be stuck or corroded), or if raising the pressure causes water to leak from the regulator itself. A plumber can also test for leaks in your system if pressure stays low after you have adjusted the regulator.

If your water company says the pressure at the meter is low, that is their responsibility to fix, not yours. Ask them what the pressure should be and whether they can increase it on their end.

Frequently Asked Questions

How much should I turn the adjustment screw?

Turn it one-quarter turn at a time, then test the pressure at a faucet. Wait a few seconds between adjustments so the system can settle. Most people find the right pressure after two to four small turns.

What if the regulator screw is stuck and will not turn?

Do not force it — you may break the screw or the regulator. Spray the screw with penetrating oil (like WD-40) and wait 15 minutes, then try again gently. If it still will not budge, a plumber can replace the regulator or free the screw.

Can I raise pressure above 80 psi if I want stronger showers?

You can, but it shortens the life of your water heater, pipes, and appliances. Pressure above 80 psi also causes water hammer — loud banging in the pipes when you turn off a faucet. Staying between 60 and 75 psi gives good shower pressure without the wear.

Why does my pressure drop when I use hot water?

Your water heater may be set too low, or the mixing valve inside it may be worn. This is not a regulator problem. A plumber can check the heater temperature and mixing valve. You can also try raising the regulator slightly, but the real fix usually involves the water heater itself.

Is it safe to adjust the regulator myself, or should I hire a plumber?

Adjusting the screw is safe — you are just turning a bolt, not cutting pipes or draining the system. If you are comfortable using a wrench, you can do it. If the screw is stuck, corroded, or you are unsure where the regulator is, a plumber is the safer choice.