Start by finding where the pressure drop happens

Low water pressure usually comes from one of three places: the main water line into your home, the pipes inside your walls, or a single fixture like a kitchen faucet. The fastest way to narrow it down is to turn on multiple faucets at once—kitchen sink, bathroom sink, shower—and see if the pressure is low everywhere or just in one spot.

If pressure is low everywhere in the house, the problem is either your main shutoff valve, the meter, or the line from the street. If it's low in only one room or one fixture, the blockage is downstream of that point. This matters because a whole-house problem usually needs a plumber, while a single-fixture problem you can often fix yourself.

Key Takeaways

  • Low pressure everywhere in the house usually means your main shutoff valve is partially closed, your water meter is clogged, or your service line is blocked—call a plumber for the meter or service line.
  • Low pressure in one fixture is often a clogged aerator (the screen at the faucet tip), which you can unscrew and clean in minutes.
  • Mineral buildup in pipes happens slowly over years and affects older homes more than new ones; a plumber can flush the line or replace sections.
  • If pressure dropped suddenly after a repair or construction work, sediment may have loosened inside the pipes and is clogging aerators and screens.
  • Check your water bill for sudden spikes, which signal a leak in the line before the meter—a problem only the water company can fix.

Check and adjust the main shutoff valve

Your main shutoff valve is usually near the water meter, in a basement, crawl space, or outside in a box in the yard. It looks like a lever or a round knob. If someone turned it partially closed—which happens more often than you'd think—it will cut pressure to the whole house.

Turn the lever all the way to the left (or the knob counterclockwise) until it stops. Do not force it. If you have a round knob and it turns freely without resistance, it may be broken and you'll need a plumber to replace it. After you adjust it, turn on a faucet and wait 30 seconds to see if pressure improves.

Clean the aerator on a single low-pressure faucet

If only one faucet has low pressure, the aerator—a small screen at the tip of the spout—is almost certainly clogged with sediment or mineral deposits. This is the easiest fix you can do yourself.

Unscrew the aerator by hand (turn counterclockwise). If it's stuck, wrap a cloth around it and use pliers, but be gentle so you don't crack the faucet. Rinse the aerator under running water and use an old toothbrush to scrub away any white or tan buildup. If the screen is badly corroded, you can buy a replacement aerator at any hardware store for a few dollars. Screw it back on and test the pressure.

Look for leaks and check your water meter

A leak in the line between the meter and your house will reduce pressure everywhere. Walk around your property—basement, crawl space, yard—and look for wet spots, puddles, or the sound of running water when all faucets are off. If you find a leak, you'll need a plumber.

Also check your water meter. If the dial is spinning when no water is running, you have a leak somewhere. If the meter itself looks corroded or clogged (the inlet screen is blocked), that can reduce pressure too. A clogged meter is a job for your water company—call them and they'll inspect it for free. If the meter is broken, they usually replace it at no cost.

Flush sediment from the pipes after a water main break

If pressure dropped suddenly after your city did work on the water main, or after a plumber worked on your line, sediment has probably loosened inside the pipes. This sediment clogs aerators and screens throughout the house.

Turn on the lowest faucet in your home (usually a basement or outdoor spigot) and let it run for 5 to 10 minutes. The water may look cloudy or brown at first—that's the sediment. Once it runs clear, turn on the other faucets one at a time and repeat. This usually clears the problem. If it doesn't, or if pressure is still low after a week, call a plumber to flush the main line.

Understand mineral buildup in older pipes

In homes with hard water or older galvanized steel pipes, mineral deposits build up inside the pipe walls over decades. This narrows the pipe opening and reduces flow. It happens slowly, so you might not notice until one day the pressure is noticeably lower than it used to be.

There's no quick fix for this. A plumber can use a hydro-jetting service to blast the inside of the pipes clean, though this is expensive and not always permanent. The longer-term solution is to replace the affected section of pipe with modern copper or PEX, which doesn't corrode the same way. If you're considering this, get quotes from two or three plumbers—costs vary widely depending on how much pipe needs replacing and how straightforward it is to access.

When to call a plumber

Call a plumber if pressure is low everywhere and the main shutoff valve is fully open, if you find a leak, if the meter is clogged, or if low pressure started after you had work done and flushing didn't fix it. A plumber can test the pressure with a gauge, find blockages, and determine whether the problem is in your line or the city's.

If you rent, contact your landlord or property manager first—they're responsible for fixing the water line. If you own the home and the problem is between the meter and the street, the water company handles it. If it's between the meter and your house, it's your responsibility.

Frequently Asked Questions

Can low water pressure damage my appliances?

Low pressure won't damage most appliances, but it can slow them down—dishwashers and washing machines may not fill properly or clean as well. If pressure is very low, some tankless water heaters won't turn on at all. Once you fix the pressure, the appliances will work normally again.

Is low water pressure a sign of a serious leak?

Not always. A small leak in a buried line might not show up as a puddle but will reduce pressure slightly. Check your water bill for a sudden jump—if it doubled or tripled, you likely have a leak. A plumber can use a listening device to find it.

Why is my water pressure low only in the morning?

This usually means the water company is doing maintenance on the main, or there's high demand in your area early in the day. Pressure should return to normal by mid-morning. If it stays low all day, the problem is in your home or your service line.

Can I increase water pressure myself without calling a plumber?

You can clean aerators and check the main shutoff valve yourself. Beyond that, you'll need a plumber. Some homes have a pressure regulator (a bell-shaped device on the main line) that can be adjusted, but this requires a plumber and a pressure gauge to do safely.

What's the difference between low pressure and low flow?

Low pressure means weak force coming out of the faucet. Low flow means less water volume overall. They often happen together, but a plumber can diagnose which one you have by measuring pressure with a gauge. The fix depends on which problem you have.