Check Your Main Water Valve and Pressure Regulator First
Low water pressure usually comes from one of three places: your main shutoff valve is partially closed, your pressure regulator is set too low, or there is a leak somewhere in your line. Start by finding your main water shutoff valve, which is typically near the street or at the foundation of your house where the water line enters. It should be fully open—turn it counterclockwise until it stops. If someone closed it partway, this alone may restore your pressure.
Next, locate your pressure regulator, a bell-shaped or cylindrical device usually mounted on the main water line just after the shutoff valve. Most regulators have a pressure gauge on top showing the current reading in pounds per square inch (PSI). Normal household pressure runs between 40 and 80 PSI. If your gauge reads below 40 PSI and your main valve is fully open, the regulator may need adjustment or replacement. If you do not see a gauge, you can buy an inexpensive water pressure gauge at any hardware store and screw it onto an outdoor faucet to check your actual pressure.
Key Takeaways
- Your main shutoff valve and pressure regulator are the first things to check—a partially closed valve or a regulator set below 40 PSI will reduce pressure throughout the house.
- You can adjust most regulators by turning the adjustment screw on top, but turning it too high can damage pipes and fixtures.
- Mineral buildup in aerators and showerheads is a common cause of low pressure in one room or fixture only.
- Leaks in your water line or inside walls will lower pressure and waste water, so look for wet spots, soft ground, or unusually high water bills.
- If pressure is low only at hot water taps, the problem is likely in your water heater or its shutoff valve, not your main line.
Adjust Your Pressure Regulator
If your pressure regulator is set below 40 PSI, you can usually raise it by turning the adjustment screw on top of the regulator clockwise. Most regulators have a locknut below the adjustment screw—loosen this first by turning it counterclockwise with a wrench, then turn the adjustment screw clockwise in quarter-turn increments. After each turn, check your pressure gauge on the outdoor faucet to see if you have reached your target (usually 50 to 60 PSI for most homes).
Do not raise pressure above 80 PSI. High pressure stresses pipes, fixtures, and appliances, and can cause leaks in walls or under the house that are expensive to repair. Once you have set the pressure where you want it, tighten the locknut again to lock the adjustment in place. If the regulator will not hold pressure or if adjusting the screw makes no difference, the regulator has failed internally and needs replacement—this is a job for a plumber, as it requires shutting off the main water and unbolting the old regulator.
Clean Aerators and Showerheads to Remove Mineral Buildup
If pressure is low at only one faucet or showerhead, the problem is almost certainly mineral deposits clogging the aerator—the small screen at the faucet tip. Unscrew the aerator by turning it counterclockwise by hand or with a wrench if it is stuck. Soak it in a bowl of white vinegar for 30 minutes to dissolve mineral buildup, then use an old toothbrush to scrub away any remaining deposits. Rinse it thoroughly and screw it back on.
For showerheads, the same method works: unscrew the head, soak it in vinegar, scrub, and reinstall. If the aerator or showerhead is heavily corroded or has a cracked screen, replace it with a new one from any hardware store—they cost between three and fifteen dollars. This fix takes ten minutes and solves low pressure at that single fixture without affecting the rest of the house.
Look for Leaks in Your Water Line
A leak in your main water line or inside your walls will lower pressure throughout the house and waste water. Check for obvious signs: wet spots in your yard, soft or muddy ground near the foundation, or a hissing sound near the main shutoff valve. If you suspect a leak, turn off all faucets and appliances, then check your water meter. If the meter is still running, you have a leak somewhere.
Small leaks inside walls are harder to spot but show up as unusually high water bills or damp patches on walls or ceilings. If you find a leak outside the house, you will need a plumber to dig up and repair the line. If the leak is inside a wall, a plumber can use a listening device to pinpoint it. Fixing a leak restores pressure and stops water waste, so this is worth investigating if pressure dropped suddenly or if your bill has climbed without explanation.
Isolate Hot Water Pressure Problems
If pressure is low only when you turn on hot water, the problem is not your main line—it is your water heater or the shutoff valve feeding it. Check the shutoff valve on the cold water line going into your water heater (usually a ball valve with a handle). Make sure the handle is parallel to the pipe, meaning the valve is fully open. If it is perpendicular to the pipe, turn it parallel.
If that valve is already open, the issue may be inside the water heater itself. Sediment buildup at the bottom of the tank can clog the outlet, reducing flow. A plumber can flush the tank to clear the sediment, or you may be able to do this yourself if your heater has a drain valve at the bottom—consult your heater's manual or a plumber before attempting this. If the heater is more than ten years old and pressure remains low after flushing, the heater may be failing and need replacement.
Know When to Call a Plumber
Call a plumber if your main shutoff valve is fully open, your pressure regulator is set correctly but pressure is still below 40 PSI, or if you suspect a leak you cannot locate. You should also call if adjusting the regulator makes no difference, if the regulator itself is leaking, or if low hot water pressure persists after checking the water heater shutoff valve. A plumber has tools to test pressure at different points in your system and can identify whether the problem is in your house or in the water line from the street.
If your entire neighborhood has low pressure, the problem is with your water utility, not your house. Contact your water company to report it—they may be doing maintenance or there may be a main line break. In this case, there is nothing you can do at home except wait for the utility to fix the issue.
Frequently Asked Questions
Can I raise water pressure above 80 PSI?
You should not. Pressure above 80 PSI damages pipes, fixtures, and water heaters over time and can cause leaks inside walls that are expensive to find and repair. If you need more flow for a specific task like filling a pool, use a temporary booster pump instead of permanently raising your main pressure.
Why is my water pressure low only in the morning?
Morning low pressure often happens because the water utility is doing maintenance or because demand is very high in your neighborhood at that hour. If it happens every morning, contact your water company. If it happens only occasionally, it is likely utility-side and will resolve on its own.
Does a water softener reduce pressure?
A water softener can reduce pressure slightly if it is clogged with mineral buildup or if it is undersized for your household flow. Check the softener's manual for cleaning instructions, or have a technician service it. If pressure drops after a softener is installed, it may need to be adjusted or replaced with a larger unit.
What is normal water pressure for a house?
Normal household water pressure is between 40 and 80 PSI. Most people find 50 to 60 PSI comfortable for showers and everyday use. Below 40 PSI, showers feel weak and filling bathtubs takes a long time. Above 80 PSI, you may hear pipes bang or rattle when you turn off a faucet.
Can low water pressure damage my appliances?
Pressure below 20 PSI can prevent dishwashers and washing machines from filling properly, which may trigger error codes or leave them unable to run. Pressure above 100 PSI can damage water heaters, ice makers, and washing machine inlet valves. Keeping pressure between 40 and 80 PSI protects your appliances and extends their life.