Check Your Main Water Shut-Off Valve First

The fastest way to raise water pressure is often the simplest: your main shut-off valve may not be fully open. This valve sits where the water line enters your home, usually in the basement, crawl space, or near the foundation. It looks like a round knob or a lever handle. If it is a knob, turn it counterclockwise until it stops. If it is a lever, make sure it points in line with the pipe—not across it.

Many homeowners find their valve was never opened all the way, or it was partially closed during a repair and never reopened. Turn it slowly and give the system a few minutes to stabilize. You should notice pressure increase at every faucet in the house. If the valve is already fully open, move to the next step.

Key Takeaways

  • Your main shut-off valve should be fully open; a partially closed valve is the most common cause of low pressure throughout the entire house.
  • A clogged aerator on a single faucet is usually the culprit if only one sink or shower has weak pressure.
  • Sediment buildup in your water heater reduces pressure to hot-water lines and can be flushed out without calling a plumber.
  • If pressure is low everywhere and your valve is open, a pressure regulator may be set too low and can be adjusted upward.
  • Leaks in supply lines and mineral deposits in pipes are harder to fix yourself and may require professional help.

Clean the Aerator on a Single Faucet

If only one sink, shower, or faucet has weak pressure, the aerator is usually the problem. The aerator is the small screen at the tip of the faucet where water comes out. Sediment, mineral deposits, and debris collect there and block flow. Unscrew it by hand or with a wrench—turn counterclockwise—and rinse it under running water. Use an old toothbrush to scrub away any buildup.

If the aerator is heavily clogged, soak it in white vinegar for 30 minutes to dissolve mineral deposits, then scrub again. Screw it back on and test the pressure. This takes five minutes and costs nothing. If pressure is still weak at that faucet after cleaning the aerator, the problem is deeper in the line and you may need a plumber.

Flush Sediment from Your Water Heater

If only your hot water has low pressure, sediment inside the water heater is likely blocking the outlet. Over time, minerals in the water settle at the bottom of the tank and reduce flow. You can flush the tank yourself if you are comfortable with basic plumbing steps.

Turn off the power to the 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 10 to 20 minutes. Close the valve, remove the hose, and turn the power back on. Wait 30 minutes for the tank to refill, then test hot water pressure at a faucet.

If you are not comfortable doing this, a plumber can flush the tank in under an hour. Do not skip this step if sediment is the cause—it will only get worse and can eventually damage the heater.

Adjust Your Pressure Regulator

If pressure is low everywhere in the house and your main valve is fully open, a pressure regulator may be set too low. This device sits on the main water line (usually near the shut-off valve) and controls how much pressure enters your home. It looks like a small brass cylinder with a screw on top or a dial on the side.

Most regulators are preset to 50 to 60 pounds per square inch (PSI). If yours is set lower, you can raise it. For a screw-top regulator, turn the screw clockwise a quarter turn, then test pressure at a faucet. Adjust in small increments—a quarter turn at a time—until pressure feels right. Do not exceed 80 PSI, which can damage pipes and appliances.

If your regulator has a dial, you can read the current setting directly. Write down the number, then turn the adjustment screw clockwise to raise it by 5 to 10 PSI. Test and adjust again if needed. If you are unsure how to adjust yours, a plumber can do it in 15 minutes.

Look for Leaks in Supply Lines

A leak in the main water line or supply pipes reduces pressure throughout the house because water is escaping before it reaches your faucets. Check under sinks, in the basement, and along visible pipes for dripping water or wet spots on walls and floors. If you see water pooling or staining, a leak is likely the cause.

Small leaks in accessible pipes can sometimes be patched with epoxy putty or a pipe repair clamp as a temporary fix, but a plumber should replace the damaged section permanently. If the leak is in the main line underground, you will need professional help to locate and repair it. Do not ignore leaks—they waste water and can cause structural damage.

Understand Mineral Buildup in Pipes

In areas with hard water, minerals accumulate inside pipes over years and narrow the passages water flows through. This happens slowly and affects pressure throughout the house. Unlike an aerator, you cannot clean the inside of pipes yourself without specialized equipment.

A plumber can use a process called hydrojetting to blast mineral deposits out of pipes, but this is expensive and is usually only done if pressure loss is severe. A more practical long-term solution is to install a water softener, which removes minerals before they enter your pipes. This prevents future buildup but does not reverse damage already done.

If you live in a hard-water area and pressure has dropped gradually over years, mineral buildup is likely. Ask a plumber to inspect your pipes before deciding on a solution.

When to Call a Plumber

You can handle the quick fixes yourself: opening the main valve, cleaning an aerator, and flushing the water heater. These take minutes and cost nothing. If pressure is still low after you have tried these steps, the problem is likely inside the pipes or the main line, and a plumber will need to diagnose it.

Call a plumber if you find a leak, if pressure remains low after adjusting the regulator, or if pressure dropped suddenly (which often signals a break in the line). A service call usually costs $100 to $200, but a plumber can pinpoint the problem in one visit and tell you what repair will cost.

Frequently Asked Questions

Why is my water pressure low in just the shower?

The shower head aerator is probably clogged. Unscrew the head, soak it in vinegar for 30 minutes, and scrub with a toothbrush. If that does not work, the problem may be in the shower valve itself, and you may need a plumber to replace it.

Can low water pressure damage my pipes?

Low pressure itself does not damage pipes, but the cause might. A leak will eventually cause water damage to walls and foundations. Mineral buildup can eventually block pipes completely. Address the cause rather than ignoring low pressure.

What is normal water pressure?

Most homes have 40 to 80 PSI. Anything below 40 PSI feels weak. Above 80 PSI can damage fixtures and appliances. If you want to measure yours, a plumber can install a pressure gauge on an outdoor faucet for about $50.

Will a water softener fix low pressure?

A water softener prevents future mineral buildup but does not remove deposits already inside your pipes. It is a long-term solution, not a quick fix for current low pressure.

Is it safe to adjust my pressure regulator myself?

Yes, if you make small adjustments and do not exceed 80 PSI. Turn the screw a quarter turn at a time and test pressure before adjusting again. If you are uncomfortable, a plumber can adjust it in 15 minutes.