Start with the simplest fixes first
Low water pressure usually comes from one of three places: a closed valve, a clogged aerator, or a problem at the meter. Before you call a plumber, check whether the issue is in your whole house or just one faucet. Turn on a sink, a shower, and an outdoor spigot. If only one fixture has weak pressure, the problem is local to that fixture. If your whole house is affected, the issue is in your main line or meter.
The fastest fix is often the simplest. Look under your kitchen sink and in your basement or crawlspace for the main water shut-off valve — it looks like a wheel or a lever on the pipe coming in from outside. Make sure it is fully open. A valve that is only partially turned can cut your pressure in half. If the valve is already open, move to the next step.
Key Takeaways
- Low pressure in one faucet usually means a clogged aerator, which you can clean by unscrewing the screen at the faucet tip and rinsing it under running water.
- Low pressure throughout your whole house points to a closed valve, a clogged meter, or a leak in your main line — check the shut-off valve first.
- If pressure drops suddenly after a plumbing repair or new construction nearby, sediment in your pipes is the likely cause and will usually clear on its own within a few days.
- A pressure regulator that has failed will cause weak pressure everywhere and needs replacement by a licensed plumber.
- Water leaks between your meter and your house reduce pressure and waste water; you can spot them by checking whether your meter keeps running when all fixtures are off.
Clean the aerator if only one faucet is weak
An aerator is the small screen at the tip of your faucet that mixes air into the water stream. Over time, mineral deposits and sediment clog it, and pressure drops at that one fixture. This is the most common cause of low pressure in a single sink or shower.
Unscrew the aerator by hand or with a wrench — it twists off counterclockwise. Rinse it under hot running water and use an old toothbrush to scrub away any white or brown buildup. If the screen is heavily clogged, soak it in white vinegar for an hour, then scrub again. Screw it back on and test the pressure. If that does not work, the aerator may be damaged and needs replacement — they cost a few dollars at any hardware store.
If you have an older faucet with no visible aerator, or if cleaning it does not help, the problem may be inside the faucet body itself. Mineral buildup inside the valve is harder to fix and usually requires a plumber to disassemble and clean the cartridge or replace it.
Check for a leak between your meter and house
A leak in the main line between your water meter and your house will reduce pressure throughout your home and waste water. To check for a leak, turn off every faucet, toilet, and appliance that uses water. Then look at your water meter — the dial should stop moving. If it keeps spinning, you have a leak.
If you find a leak, the next step is to locate it. Walk your property looking for wet spots, soft ground, or unusually green patches of grass. If the leak is underground and you cannot see it, you will need a plumber with leak detection equipment. Leaks in the main line are not something you can fix yourself — they require excavation and pipe replacement.
In the meantime, the leak is costing you money and water. Contact your water utility to report it; some utilities offer rebates or credits for main line leaks once you have had them repaired.
Flush sediment from your pipes after construction or repairs
If your pressure dropped suddenly after a plumbing repair, new construction nearby, or work on the water main, sediment in your pipes is almost certainly the cause. When pipes are disturbed, rust, mineral deposits, and debris get knocked loose and travel through your lines, clogging aerators and reducing flow.
The fix is to flush your system. Turn on your lowest faucet — usually an outdoor spigot or a basement sink — and let it run at full pressure for 5 to 10 minutes. You may see brown or cloudy water at first; keep running it until the water runs clear. Then do the same at your highest faucet. This pushes the sediment through and out of your system.
If pressure is still low after flushing, sediment may have settled in your aerators. Remove and clean every aerator in your house using the method described above. Sediment clogs usually clear within a few days on their own, but cleaning aerators speeds up the process.
Test your water pressure with a gauge
If you have ruled out straightforward fixes and want to know whether your pressure is actually low or just feels that way, a pressure gauge costs about ten dollars at any hardware store. Screw it onto an outdoor spigot or a faucet with a removable aerator. Turn the water on fully and read the number.
Normal household water pressure is between 40 and 80 pounds per square inch (PSI). If your reading is below 40 PSI, you have genuinely low pressure. If it is between 40 and 80, your pressure is normal and the problem may be something else — a slow-filling toilet, for example, or a fixture that is straightforward old and restrictive.
Write down your pressure reading. If you end up calling a plumber, this number tells them whether the problem is in your house or in the water main, and it helps them diagnose what is wrong.
Understand when you need a plumber
Call a plumber if your pressure is below 40 PSI and you have ruled out closed valves, clogged aerators, and sediment. The problem is likely a failed pressure regulator, a clogged meter, or a leak in the main line — all of which require professional tools and licensing.
A pressure regulator is a valve that sits where the water line enters your house and keeps pressure from getting too high. If it fails, pressure drops throughout your home. Replacement usually costs between 150 and 300 dollars and takes an hour or two.
A clogged meter is less common but happens when sediment builds up inside the meter itself. The water utility may handle this repair at no cost, so call them first before hiring a private plumber. If the problem is a leak in the main line, expect to pay for excavation and pipe replacement, which varies widely depending on how deep the pipe is and how long the damaged section is.
Know the difference between low pressure and low flow
Low pressure and low flow are not the same thing. Low pressure means weak force — water comes out slowly even when the valve is fully open. Low flow means the total amount of water is restricted — a toilet fills slowly, or a shower takes a long time to fill a bucket, even though the spray feels normal.
Low flow is usually caused by a clogged aerator or a partially closed valve, and the fixes above will solve it. Low pressure is a system-wide problem and points to something wrong with the main line, the meter, or the regulator. If you are not sure which one you have, use the pressure gauge test described above.
Frequently Asked Questions
Why is my water pressure low only in the morning?
Morning low pressure is usually caused by overnight sediment settling in your pipes or aerators. Run your lowest faucet for a few minutes to flush the system, then check pressure again. If it returns to normal, sediment is the culprit. If it stays low, the problem is something else.
Can a water softener cause low pressure?
Yes. Water softeners add resistance to your water line, and if the unit is old or clogged with mineral buildup, it can reduce pressure noticeably. Check the softener's filter or cartridge and replace it if it is dirty. If pressure does not improve, the softener itself may need servicing or replacement.
What should I do if pressure is high, not low?
High pressure — above 80 PSI — can damage pipes and appliances over time. Install a pressure regulator if you do not have one, or have a plumber check your existing regulator. High pressure is less common than low pressure but more damaging if left alone.
Does cold weather affect water pressure?
Yes. Frozen pipes restrict flow and reduce pressure. If pressure drops in winter and returns in spring, a frozen section of pipe is likely. Thaw it by explore heat to the affected area with a heat lamp or heating pad. If the pipe bursts, you will need a plumber to repair it.
How long does it take for sediment to clear on its own?
Sediment usually settles out within a few days to a week. Flushing your system speeds this up. If pressure is still low after a week, sediment is not the cause and you should investigate other possibilities.