Check Your Main Water Shut-Off Valve First
The fastest fix for low water pressure is often a valve you can adjust yourself. Your main water shut-off valve — the one that controls water flow into your entire house — may be partially closed. This valve sits where the water line enters your home, usually in the basement, crawl space, or outside near the foundation. It looks like a round knob or a lever handle.
If it's a round knob, turn it counterclockwise (left) a few full rotations. If it's a lever, make sure it points in line with the pipe — that means it's fully open. Turn it slowly and check your faucets after each adjustment. You should feel pressure increase within seconds. Many homeowners find this solves the problem without calling a plumber.
If the valve is already fully open or turning it makes no difference, move to the next step. Do not force a stuck valve — that can damage it and you may need a professional to replace it.
Key Takeaways
- Your main water shut-off valve may be partially closed, and opening it fully is the cheapest first step to try.
- A clogged water meter or mineral buildup in your pipes can reduce pressure throughout the house, and a plumber can clear these.
- Low pressure in one room only usually means a clogged aerator on that faucet, which you can clean yourself in five minutes.
- A pressure regulator that has failed will cause pressure to drop gradually, and replacing it costs $200 to $400 in most homes.
- If your city's water main is being worked on, pressure will return once repairs finish — call your water department to confirm.
Clean or Replace Clogged Aerators on Individual Faucets
If only one sink, shower, or faucet has weak pressure, the problem is almost always the aerator — a small screen at the tip of the faucet that mixes air into the water. Mineral deposits and sediment clog it over time, especially in areas with hard water.
Unscrew the aerator by hand or with a wrench if it's tight. It's the part that unscrews from the very end of the faucet spout. Rinse it under hot water and use an old toothbrush to scrub away white or brown buildup. If it's heavily clogged, soak it in white vinegar for 30 minutes, then scrub again. Screw it back on and test the pressure.
If cleaning does not help, the aerator may be damaged inside. Buy a replacement at any hardware store for $3 to $8 — they are universal and take 30 seconds to install. This solves the problem in most single-faucet cases.
Flush Your Water Meter and Check for Leaks
Your water meter can become clogged with sediment from the city water line, especially after construction or main breaks in your neighborhood. This reduces pressure throughout the whole house. You can flush it yourself before calling a plumber.
Locate your water meter — it's usually in a box in your front yard or basement. Turn the shut-off valve next to it fully closed, wait 30 seconds, then open it again. This can dislodge sediment. If pressure improves, you are done. If not, the meter itself may need professional cleaning or replacement by your water department.
While you have the meter visible, check for leaks. Look for wet soil around the meter box or listen for running water when no faucets are on. A leak between the meter and your house will reduce pressure. Call your water department — they usually fix leaks on their side of the meter for free, and you pay only if the leak is on your property.
Inspect Your Pressure Regulator
Most homes have a pressure regulator — a bell-shaped device on the main water line that keeps pressure from getting too high and damaging pipes. If this regulator fails, pressure will drop gradually over days or weeks. You may notice it if pressure was normal last week and is now weak everywhere in the house.
The regulator sits on the main water line just after the shut-off valve, usually in the basement. It has a screw adjustment on top. Try turning that screw clockwise (right) a quarter turn, then check your pressure. If it improves slightly, you may have found the problem — but a failing regulator usually needs replacement, not adjustment.
Replacing a pressure regulator costs $200 to $400 including labor, depending on your region and plumber rates. This is a job for a licensed plumber because it involves cutting into the main water line. Call a plumber if you suspect the regulator is the cause.
Look for Leaks in Your Pipes
A hidden leak in your walls or under your foundation will reduce pressure throughout the house. You may not see water, but you will notice pressure drop slowly over time, and your water bill will jump.
Check your water meter when no one is using water — not even the toilet running or ice maker filling. Write down the number. Wait two hours without using any water. Check the meter again. If the number changed, you have a leak. The size of the change tells you how serious it is.
Call a plumber with leak detection equipment. They can pinpoint the leak without tearing into walls. Repair costs vary widely depending on where the leak is and how accessible it is, but finding it quickly prevents water damage and mold. Do not ignore a leak — it will only get worse.
Check With Your Water Department About City-Side Issues
Sometimes low pressure is not your problem to fix. Your city's water main may be under repair, or a break may have reduced pressure in your neighborhood. Call your water department's customer service line and ask if there are any known issues in your area.
Main breaks and repairs are temporary. Pressure will return once the work is done. The water department can tell you how long repairs usually take. If they confirm a city-side issue, you do not need to do anything — just wait for service to return to normal.
If your water department says there are no known issues, that confirms the problem is on your property, and you should focus on the steps above.
When to Call a Plumber
You can handle aerator cleaning and checking your shut-off valve yourself. Everything else — flushing the meter, diagnosing a failing regulator, finding hidden leaks, or replacing the regulator — is worth calling a plumber for. A service call usually costs $100 to $200, and a plumber can identify the real cause in one visit instead of you guessing.
If you have tried opening the shut-off valve and cleaning aerators and pressure is still low everywhere, call a plumber. They have tools to measure actual pressure (normal is 40 to 80 pounds per square inch) and can tell you exactly what is wrong. Many plumbers offer free estimates, so get a quote before committing to the repair.
Frequently Asked Questions
Why is my water pressure low in only the hot water?
The problem is usually in your water heater or the pipes leading to it. Sediment builds up inside the heater tank over time and blocks flow. Drain your water heater by turning off the gas or electricity, attaching a hose to the drain valve at the bottom, and opening it. Let water run until it runs clear. If that does not help, the heater may need replacement.
Can I increase water pressure by adjusting the pressure regulator myself?
You can try turning the adjustment screw a quarter turn clockwise, but this is a temporary test only. If the regulator itself is failing, adjustment will not fix it permanently. A plumber should diagnose whether the regulator needs replacement or if something else is causing low pressure.
Does a water softener reduce water pressure?
A water softener can reduce pressure slightly, especially if it is old or clogged with mineral buildup. If you have a softener and pressure dropped suddenly, have it serviced or backflushed. A new softener should not cause noticeable pressure loss in a properly sized system.
What is normal water pressure for a house?
Normal household water pressure is between 40 and 80 pounds per square inch (PSI). Anything below 40 PSI feels weak, and above 80 PSI can damage appliances and pipes. A plumber can measure your actual pressure with a gauge that costs about $10 to buy.
Will low water pressure affect my water heater?
Low pressure will not damage a water heater, but it may prevent it from working properly. Some heaters need a minimum pressure to ignite the burner or set up the heating element. If you have low pressure and your heater is not heating, pressure may be the cause — fix the pressure problem first.