Check Your Main Water Shut-Off Valve First
The fastest fix for low water pressure is often a partially closed shut-off valve. This valve controls all water entering your home and sits where the main water line comes in from the street—usually in a basement, crawl space, or utility closet near the foundation. If someone turned it partway closed for a repair and didn't fully reopen it, your pressure drops when ready.
Look for a gate valve (shaped like a wheel) or a ball valve (shaped like a lever). Turn a gate valve counterclockwise until it stops. Turn a ball valve so the lever points in line with the pipe. Do this slowly and listen for pressure changes at your faucets. If pressure jumps back to normal within a minute, that was your problem. If nothing changes, move to the next step.
Key Takeaways
- A partially closed main shut-off valve is the most common cause of low pressure and takes 30 seconds to check and fix.
- Mineral buildup in aerators and showerheads can be cleaned with vinegar and a brush without calling a plumber.
- A pressure regulator that has failed will need replacement, but this is a straightforward job that costs under $200 in parts and labor.
- If only one fixture has low pressure, the problem is local to that line; if the whole house is affected, the issue is in the main line or meter.
- Water company pressure varies by neighborhood and time of day, so check with your utility before assuming your system is broken.
Clean Aerators and Showerheads of Mineral Buildup
Mineral deposits from hard water clog the small screens in faucet aerators and showerheads. This narrows the opening and reduces flow even though pressure behind the line is normal. You can clean these in 10 minutes with white vinegar and a toothbrush.
Unscrew the aerator from the faucet tip (most twist off by hand; use pliers if it is stuck). Soak it in a cup of white vinegar for 30 minutes, then scrub the screen with an old toothbrush to dislodge the white or brown mineral crust. Rinse under running water and screw it back on. Do the same for showerheads. If pressure returns to normal at that one fixture, you have found the problem. If low pressure is still happening at multiple fixtures throughout the house, the blockage is deeper in your lines.
Test Your Water Pressure with a Gauge
Before you spend money on repairs, measure your actual pressure. Normal household pressure is 40 to 60 pounds per square inch (psi). Below 40 psi feels weak; above 80 psi can damage pipes and appliances. A pressure gauge costs $10 to $15 at any hardware store and screws onto an outdoor faucet or a hose bib in your basement.
Turn off all water use in the house—no showers, washing machines, or toilets running. Screw the gauge onto the faucet and read the number. Write it down. If your reading is below 40 psi, you have a real pressure problem. If it is between 40 and 60 psi, your pressure is normal and the issue may be something else, like a clogged aerator you missed or a fixture-specific problem. Call your water company and ask what pressure they deliver to your neighborhood; if they say 50 psi and you are reading 48 psi, your system is working correctly.
Adjust or Replace Your Pressure Regulator
A pressure regulator is a bell-shaped device on the main water line (usually near the shut-off valve) that keeps incoming pressure from the street from damaging your home's pipes. If it fails or gets stuck, pressure drops. Some regulators have an adjustment screw on top that you can turn to raise pressure; others cannot be adjusted and must be replaced.
Check your regulator's label or manual to see if it is adjustable. If it has a screw, turn it clockwise a quarter turn at a time, wait 30 seconds, and check your pressure gauge. Stop when you reach 50 to 60 psi. Do not exceed 80 psi. If the regulator has no adjustment screw, or if adjusting it does not help, it needs replacement. This is a job most homeowners can do: turn off the main shut-off valve, unscrew the old regulator, wrap the threads of the new one with plumber's tape, and screw it in hand-tight. If you are not comfortable doing this, a plumber will charge $150 to $300 for the part and labor.
Look for Leaks in Your Main Water Line
A crack or leak in the main line between the meter and your house reduces pressure throughout the home. Signs include soft spots in your yard, unusually green patches of grass, or a hissing sound near the foundation. If you suspect a leak, turn off the main shut-off valve and check your water meter. If the meter keeps running or the number keeps climbing, water is escaping somewhere.
Leaks in the main line are expensive to fix because they require digging. Call your water company first—in some places, they own and repair the line from the street to the meter, and you own everything after that. In other places, you own the entire line. Your utility can tell you who is responsible and recommend a licensed plumber. Do not ignore a leak; it wastes water and drives up your bill.
Check for Sediment in Your Water Meter
Sediment or mineral buildup inside your water meter can restrict flow. This is less common than other problems but worth checking if pressure is low throughout the house and your shut-off valve, regulator, and aerators are all clear. You cannot clean a meter yourself—it is sealed and owned by the water company—but you can call your utility and ask them to inspect it.
Tell them you have low pressure everywhere, you have checked your shut-off valve and regulator, and you want to know if the meter is the problem. Many utilities will send someone out to check for free. If sediment is the issue, they will clean or replace the meter at no cost to you.
Understand What Your Water Company Delivers
Your water company controls the pressure at the street. In some neighborhoods, pressure is consistently 60 psi. In others, it drops to 30 psi during peak hours (usually 6 to 9 a.m. and 5 to 8 p.m.) when many people are using water at once. If your pressure is low only at certain times of day, this is normal and not a problem with your home's system.
Call your water company and ask what pressure they deliver to your address and whether it varies by time of day. If they say pressure is supposed to be 50 psi and you are reading 48 psi, your system is working as designed. If they say 60 psi and you are reading 35 psi, something in your home's system is restricting flow. This conversation takes five minutes and can save you hundreds in unnecessary repairs.
Frequently Asked Questions
Can low water pressure damage my pipes or appliances?
Low pressure itself does not damage pipes, but it can be a sign of a leak that wastes water. High pressure above 80 psi can crack pipes and damage water heaters and washing machines over time. If your pressure is consistently above 80 psi, a pressure regulator will protect your system.
Why is the pressure low in only one room or one fixture?
A single fixture with low pressure usually has a clogged aerator or showerhead. If an entire room is affected, a shutoff valve under the sink may be partially closed, or a supply line to that room may be kinked or blocked. Check the aerator first, then look under sinks for valves you can turn.
Should I install a pressure booster pump?
A booster pump is expensive ($1,000 to $3,000 installed) and should be a last resort. Try the free and low-cost fixes first: check your shut-off valve, clean aerators, test your pressure, and call your water company. A booster pump makes sense only if your utility delivers consistently low pressure and you have ruled out all other causes.
What is the difference between a pressure regulator and a pressure relief valve?
A pressure regulator reduces high incoming pressure to a safe level for your home. A pressure relief valve opens only if pressure gets dangerously high, then closes again. Most homes have a regulator. You may also have a relief valve as a backup safety device, but it does not control normal pressure.
Can I increase pressure by adjusting something at the water meter?
No. The meter measures flow; it does not control pressure. The water company controls pressure at the street. You can only adjust pressure inside your home using a regulator or booster pump. If pressure from the street is low, neither of those will help much.