Check Your Main Water Valve and Pressure Regulator First

The fastest way to raise water pressure is to adjust or replace the pressure regulator, a bell-shaped device usually located where the main water line enters your home. If your pressure has dropped suddenly, the regulator may have failed or been set too low. Most regulators can be adjusted by turning a screw on top — turning clockwise increases pressure, counterclockwise decreases it. A typical home runs at 40 to 60 pounds per square inch (PSI); anything below 40 PSI will feel weak at the tap.

Before adjusting anything, measure your current pressure using a pressure gauge, which screws onto an outdoor faucet or laundry sink. These cost $10 to $20 at any hardware store. If your reading is below 40 PSI and you have a regulator, try turning the adjustment screw a quarter turn and retest. If pressure jumps above 80 PSI, turn it back down — high pressure damages pipes and fixtures over time.

If you do not have a regulator or the adjustment does not help, the problem lies elsewhere. Do not keep turning the screw; you risk damaging the device or creating a leak.

Key Takeaways

  • A pressure regulator controls water pressure at the point where the main line enters your home, and adjusting it is the quickest fix for low pressure throughout the house.
  • Measure your current pressure with a gauge before making changes; anything below 40 PSI feels weak, and anything above 80 PSI can damage pipes and appliances.
  • Mineral buildup in aerators and showerheads is the most common cause of weak flow at a single fixture, and cleaning or replacing them costs under $10.
  • Leaks in supply lines, corroded pipes, or a failing water heater can reduce pressure; a plumber can locate these with a pressure test and visual inspection.
  • If your water company supplies low pressure to your neighborhood, a booster pump can raise it, though installation typically costs $500 to $2,000.

Clean or Replace Aerators and Showerheads

If pressure is weak at only one faucet or showerhead, the problem is almost always mineral buildup inside the aerator — the small screen at the tip of the faucet. Hard water deposits clog the tiny holes and restrict flow. Unscrew the aerator by hand or with a wrench, soak it in white vinegar for 30 minutes to an hour, then scrub the screen with an old toothbrush. Rinse thoroughly and screw it back on.

If soaking does not restore flow, the aerator is too corroded to clean. A replacement aerator costs $3 to $8 and takes 30 seconds to install. Bring the old one to the hardware store to match the thread size, or take a photo of the faucet base to show the staff. Showerheads follow the same process — unscrew, soak in vinegar, scrub, and rinse. If a showerhead is permanently attached, you may need to soak it in a bag of vinegar tied around the head with a rubber band.

This fix works only for single fixtures. If pressure is low everywhere in the house, the problem is in the main line or regulator, not the aerators.

Look for Leaks in Supply Lines and Visible Pipes

A leak anywhere between the meter and your fixtures reduces pressure throughout the house. Walk your basement or crawlspace and look for wet spots, water stains, or active dripping on pipes. Check under sinks and around the water heater. Even a small pinhole leak can lower pressure noticeably over time.

If you spot a leak, mark it and call a plumber. Do not attempt to patch supply lines yourself — they are under pressure and a failed repair can cause flooding. A plumber can locate the leak with a pressure test and either repair the line or recommend replacement if corrosion is widespread.

Older homes with galvanized steel pipes often develop internal corrosion that narrows the pipe opening and reduces flow. This happens gradually and affects the whole house. If your home is over 50 years old and pressure has been dropping slowly, corrosion is likely. Replacing galvanized lines with copper or PEX is expensive but permanent; get quotes from at least two plumbers before deciding.

Inspect Your Water Heater

A failing water heater can reduce hot water pressure while cold water pressure stays normal. The tank may have sediment buildup that blocks the outlet, or the dip tube inside may have cracked, allowing hot and cold water to mix. If hot water pressure is noticeably weaker than cold, the heater is the culprit.

Flushing the tank can help if sediment is the issue. Turn off power or gas to the heater, attach a garden hose to the drain valve at the bottom, and run water into a bucket or floor drain until the water runs clear. This takes 15 to 30 minutes. If pressure does not improve, the dip tube or heating element may be failing, and the heater may need replacement.

Water heater replacement typically costs $800 to $1,500 for a standard tank model. A plumber can diagnose the problem with a visual inspection and pressure test before you commit to replacement.

Install a Booster Pump if Your Water Company Supplies Low Pressure

Some neighborhoods receive water at lower pressure than others, depending on distance from the treatment plant and local demand. If your pressure gauge reads consistently below 40 PSI and a plumber has ruled out leaks, regulator failure, and corroded pipes, low municipal pressure is the cause.

A booster pump takes incoming water and pressurizes it to a usable level. Installation requires a plumber to mount the pump near the main line, usually in the basement or utility room, and connect it to an expansion tank. The pump runs automatically whenever you open a faucet. A typical installation costs $500 to $2,000 depending on pump size and local labor rates.

Before installing a booster pump, contact your water company and ask about their standard pressure in your area. Some companies will increase pressure at the meter if you request it. This is free and worth asking before spending money on a pump.

Test Pressure After Each Change

After adjusting the regulator, cleaning aerators, or fixing a leak, retest pressure with your gauge. Screw the gauge onto the same outdoor faucet you used before, turn the faucet on fully, and read the PSI. Write down the number so you can track changes over time. If pressure is now between 40 and 60 PSI, the fix worked.

If pressure is still low after trying these steps, the problem is complex — possibly a combination of issues or a problem at the municipal level. A licensed plumber can run a full diagnostic, including a pressure test at different points in your system, to pinpoint the cause. This typically costs $100 to $200 for the visit and diagnosis.

Frequently Asked Questions

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

You can adjust it yourself if you have a pressure gauge and the regulator is accessible. Turn the adjustment screw slowly and retest after each quarter turn. If you are uncomfortable working with water lines or the regulator is stuck, call a plumber. A service call usually costs $150 to $300.

What PSI is too high for a home water system?

Anything above 80 PSI can damage pipes, water heaters, and appliances over time. High pressure causes leaks at joints and can burst supply lines. If your gauge reads above 80 PSI, lower the regulator setting or have a plumber check it.

Why is my cold water pressure strong but hot water pressure is weak?

The water heater is likely the problem. Sediment buildup or a failed dip tube reduces hot water flow while cold water bypasses the heater entirely. Flushing the tank may help; if not, the heater may need replacement.

How much does it cost to replace corroded pipes?

Costs vary widely depending on how much pipe needs replacement and whether walls or floors must be opened. A plumber can give you an estimate after inspecting the lines. Partial replacement might cost $500 to $1,500; full replacement of a whole house can exceed $5,000.

Will a booster pump work if my water company supplies very low pressure?

Yes, a booster pump can raise pressure even from very low starting levels. However, it cannot create water — if your supply is restricted at the meter, the pump will run constantly and wear out faster. Ask your water company about their pressure before installing a pump.