How to Increase Water Pressure in a House

Low water pressure in a house comes down to one of four things nearly every time: a clogged aerator or showerhead, a valve that isn’t fully open, a pressure-reducing valve (PRV) set too low, or a genuine drop in the municipal supply. Work through the cheap fixes first, cleaning fixtures and checking valves, before you assume the PRV or the water main is to blame. Most homes run comfortably between 45 and 60 psi, and anything under 40 psi at the tap counts as low. If cleaning, valve checks, and a PRV adjustment don’t fix it, stop guessing and call a licensed plumber.

What causes low water pressure in a house?

Low water pressure traces back to a short list of usual suspects, and most of them are quick to rule out:

• Clogged aerators or showerheads, where mineral deposits and sediment restrict flow at the fixture itself, not in the pipes.
• A partially closed valve, whether it’s the main shutoff, the water heater’s inlet valve, or an individual fixture stop that got bumped during a repair.
• A pressure-reducing valve set too low, since the PRV where the main line enters the house controls pressure for the whole property at once.
• Corroded or undersized pipes, which is common in older homes with galvanized steel that narrows with rust and buildup over decades.
• A municipal supply issue, where distance from the water main, elevation, or peak-demand hours lower the pressure before it’s even reached your property.

If you self-manage a rental, this is one of the more common maintenance calls you’ll field, and it’s worth building into your regular walkthroughs rather than waiting for a resident to report it. Our rental property maintenance guide for landlords covers what else belongs on that seasonal checklist.

How do you clean a clogged aerator or showerhead?

Unscrew the aerator from the faucet and the showerhead from its arm, soak the screens in white vinegar for 30 to 60 minutes to dissolve mineral buildup, scrub the mesh with an old toothbrush, then rinse and reattach. This is the fastest fix and it solves the problem more often than any other single step. If a showerhead has fixed spray holes instead of a removable screen, soak the whole head in a vinegar-filled bag secured with a rubber band instead of disassembling it. Run the faucet or shower once everything is back together, and a noticeable jump in pressure means you found the problem. No change means the clog, or the actual cause, is somewhere else.

How do you check for a partially closed valve?

Check the main shutoff valve, the water heater’s inlet valve, and any stop valves under sinks or toilets, and confirm each one is turned all the way open. A ball valve is fully open when its handle lines up with the pipe. A gate valve should turn freely until it stops, with no resistance left in the handle. These valves get closed for repairs and don’t always get reopened all the way afterward, and a valve sitting even a quarter turn short of fully open can noticeably cut flow to everything downstream of it. A valve that turns hard, looks corroded, or won’t move is a plumber call, not a wrench job.

What does a pressure-reducing valve do, and how do you adjust it?

A pressure-reducing valve sits where the main water line enters the house, usually near the main shutoff in a basement or utility closet. It’s typically bell-shaped and made of brass. It steps down incoming municipal pressure to a level the home’s pipes and fixtures can handle, and adjusting it is how you raise or lower pressure for the entire property at once. Most local plumbing codes require a PRV once incoming water pressure exceeds 80 psi static, per the International Plumbing Code, Section 604.8, the model code most US jurisdictions adopt.

To adjust it, gauge the current pressure first by screwing a water pressure gauge onto an outdoor spigot or the washing machine’s cold-water bib, making sure every other fixture in the house is off before you read it. Loosen the locking nut on top of the valve with a wrench without removing it, then turn the adjustment screw clockwise in small increments, about a quarter turn at a time, to raise pressure, or counterclockwise to lower it. Re-test with the gauge after each adjustment rather than guessing at the right setting, and once the reading lands in the 45 to 60 psi range, retighten the locking nut to hold it there.

A PRV that won’t hold a setting, or that’s leaking around the body, is failing rather than misadjusted. That’s a replacement job for a plumber, not something to keep re-tuning.

Could the municipal water supply be the problem?

The problem can start before water even reaches your property line, in the municipal supply itself, and no amount of work on your own plumbing will fix that. Call your water provider and ask about typical pressure in your area, whether there’s ongoing repair work nearby, and whether they can run a pressure test on the line before it enters your house. Homes farther from the main, at a higher elevation, or on a street with heavy peak-hour demand (early morning showers, summer irrigation) can see pressure drops that have nothing to do with your fixtures or pipes. If the utility confirms low pressure at the source, a whole-house booster pump is usually the only real fix, since cleaning aerators won’t compensate for weak supply pressure.

Should you install a water pressure booster pump?

Install a booster pump once you’ve confirmed the low pressure is coming from the supply side rather than something fixable inside the house, since a booster raises pressure and flow rate for the whole property at once. That matters most in homes with multiple bathrooms, upper floors, or several fixtures drawing water at the same time. Sizing one correctly means matching it to your fixture count and household demand, which is worth a professional assessment rather than a guess. Installation should also go to a licensed plumber, since a booster pump ties into the main line under pressure, and a bad install risks leaks or damage that costs far more than the pump itself.

When should you call a plumber?

Call a plumber once you’ve cleaned the fixtures, checked every valve, and confirmed the PRV, and pressure still hasn’t improved. A few situations are worth a call from the start rather than after you’ve tried everything else:

• Persistent low pressure with no obvious cause, which often points to buildup deep in the pipes or a problem with the main line itself.
• Older galvanized plumbing, which corrodes from the inside and usually needs a section replaced rather than cleaned.
• A leak you can’t locate, especially one hidden behind a wall or under a slab.
• Booster pump installation, which needs correct sizing and a code-compliant tie-in to the main line.

Any repair that touches the main water line or requires a permit should go to a licensed plumber, full stop. DIY work here risks code violations and water damage that’s expensive to reverse.

Handling a maintenance call like this one well, diagnosing before you dispatch and keeping a record of what was checked and fixed, is a routine part of managing a rental property day to day.

FAQ

What counts as low water pressure in a house?

Most plumbing pros consider anything under 40 psi at the fixture to be low, with a comfortable range running from 45 to 60 psi. Below that, showers, washing machines, and dishwashers all take longer to fill and perform worse.

Can I adjust my home’s water pressure regulator myself?

Yes, in most cases. Locate the PRV near the main shutoff, attach a pressure gauge to an outdoor spigot, and turn the adjustment screw clockwise to raise pressure or counterclockwise to lower it, checking the gauge after each small turn. If the valve won’t hold a setting or looks corroded, call a plumber instead of forcing it.

Will replacing old pipes increase water pressure?

Often, yes. Galvanized steel pipes corrode and narrow from the inside over decades, which restricts flow even when every fixture and valve checks out fine. Replacing corroded sections, or upgrading to larger-diameter pipe, can meaningfully improve pressure in an older home.

How do I test my home’s water pressure?

Attach a water pressure gauge, available at any hardware store, to an outdoor spigot or hose bib, turn off every other fixture in the house, and open the spigot fully. The gauge reading is your static water pressure in psi.

Do water pressure booster pumps actually work?

Yes, when the cause is confirmed to be low pressure from the municipal supply rather than something fixable inside the house. A correctly sized booster pump raises both pressure and flow rate for the whole property, but sizing and installation should go to a professional.