You can feel or hear itVery common

Why is the water pressure low throughout my whole house?

Pressure that has crept down over months is a different problem from pressure that vanished overnight, and this is the slow one. Slow decline points at something wearing or clogging rather than something that moved, and the cheapest suspect is equipment you own.

Also covers low water pressure entire house · weak water pressure everywhere · house wide low pressure

A healthy setting: 50 to 60 PSI
Free first check: Filter or softener on bypass
Free second check: Watch the meter with everything off
Regulator replacement: $300–$650 installed
A gauge on an outside tap: Settles it in five minutes

Narrow it down

Which of these applies?

The order runs free to expensive. Start with equipment you own.

Likely reasons

What else it could be

Ranked for the common case. Answer the question above and we re-rank for yours.

A valve isn’t fully open
Most common
Water reaches your house through a series of valves: the utility's curb stop at the property line, the valve at your meter, and your main shutoff inside. Any of them partly closed throttles the whole house, and they get left that way after repairs, meter work, or utility visits.
Common misdiagnosis
A lever valve at 45 degrees looks roughly open and reads as "on" to most people. It isn't. In line with the pipe, or it's restricting you.
What it costs you, and how to fix it
If you leave it
No damage, but you may spend money diagnosing a problem that a quarter-turn fixes.
What to expect
Check your main shutoff first: a gate valve (round handle) should turn fully counter-clockwise until it stops; a ball valve (lever handle) is open only when the lever is in line with the pipe, not at an angle.
Then check the valve at the meter, which is the one most often left partly closed after utility work.
The curb stop at the property line belongs to the utility; call them rather than turning it yourself.
Leak somewhere in the system
Water escaping before it reaches your taps costs you both pressure and volume, and a leak inside a wall, under a slab, or in the buried service line can run a long time unnoticed while doing real damage.
Common misdiagnosis
Weak pressure gets blamed on the city or a regulator while a leak runs unchecked. The meter test costs nothing and rules it in or out.
What it costs you, and how to fix it
If you leave it
Unlike most causes here, this one damages your house while you decide. Structural damage, mold, and a climbing water bill all compound.
What to expect
A plumber locates the leak (acoustic and pressure-testing equipment for hidden ones) and repairs it. Main water line repairs commonly run $400–$1,500 depending on location and access. Bring your meter-test result; knowing a leak is confirmed saves diagnostic time you'd otherwise pay for.
Regulator failing or drifting
A regulator works with a spring and a rubber diaphragm. Both wear. As they do, the valve stops holding a steady setting, pressure drifts down over months, swings unpredictably, or in some failures climbs instead.
Common misdiagnosis
Slow decline over months gets blamed on "the city." A gauge test at an outside tap settles it in five minutes, and if the reading is low with no municipal issue, the regulator is the first suspect.
What it costs you, and how to fix it
If you leave it
A drifting regulator can fail toward high pressure as well as low, which brings the damage described above. It also masks other problems by making everything mildly wrong.
What to expect
A plumber can sometimes adjust a regulator that's merely out of adjustment, which costs less than replacement. Most genuinely failing units need replacing: roughly $300–$650 installed. Ask for a before-and-after gauge reading so you can see what you paid for.
Your filter or softener is the restriction
Whole-house filters and softeners sit on your main line, so everything downstream passes through them. A cartridge loaded with sediment, a fouled or channeled resin bed, a salt bridge, or a bypass valve left partly closed all throttle the entire house.
Common misdiagnosis
People rarely suspect their own filtration, so this one hides for months. It's also worth saying plainly: we sell filtration, and we're still telling you to check it first. A filter that's throttling your house needs service, not a plumber.
What it costs you, and how to fix it
If you leave it
Nothing dangerous, but you'll keep chasing a plumbing problem you don't have, and a clogged cartridge means the media isn't treating your water well either.
What to expect
The bypass test settles it in minutes: put the system on bypass and see whether pressure returns. If it does, the equipment is the cause: change the cartridge, check the bypass valve is fully open, or have the resin serviced.
If pressure stays low on bypass, the cause is upstream and we'll route you onward.
The supply line is too small
Static pressure and flow are different things. A narrow service line (the pipe from the street to your house) can deliver perfectly normal pressure when nothing is running, then fall apart the moment two fixtures open, because it can't carry enough volume.
Older half-inch lines are the usual culprits in homes with modern fixture counts.
Common misdiagnosis
This gets treated as low pressure and "fixed" by adjusting or replacing a regulator, which changes nothing; the regulator was never the limit. Volume problems need bigger pipe, not more pressure.
What it costs you, and how to fix it
If you leave it
Not damaging, but it caps what your plumbing can ever deliver, and it gets more noticeable as households add fixtures and appliances.
What to expect
First, rule out the cheaper restrictions that look identical: a clogged whole-house filter, a partly closed valve, a failing backflow device, or corroded galvanized pipe inside the house. If those are clear, a plumber can evaluate the service line size and what upsizing would involve. It's a real excavation job, so get the diagnosis confirmed before committing.

What this means

What this means for you

Changes with your answer above. Then two ways to know for sure.

A gradual decline is worth checking on your side first: regulators, filters and old pipe wear over months. Ask a neighbor first to rule out the street. The order to check it in runs from free to expensive: your own filter, then the meter test for a leak, then a gauge reading on an outside tap, and only then a plumber.

Most of what’s on this page comes down to two things you can check yourself, today, for almost nothing:

Start hereFree

Rule out the two cheapest answers

Ask a neighbor
If the whole neighborhood has lost pressure too, the problem is most likely outside your house.
Watch the meter
Shut every tap and monitor the meter. A meter that still creeps means water is escaping, and a hidden leak is the only cause here that gets worse while you decide.

If both come back clear, the problem sits on your side of the meter. That is the point to call a plumber.

Ground truth

Measure your pressure twice, day and night

Screw a gauge onto an outside tap and take one reading in the daytime, one late at night. City pressure often rises overnight as demand falls, so a much higher night reading can point to a missing or failing regulator.

A pressure gauge is an inexpensive hardware-store part.

What your reading meansUnder 50Below the range to aim for50 to 60The range to aim forOver 80Above the code ceilingThe 80 PSI ceiling is code, not opinion: the plumbing code caps static pressure there and requires a regulator above it.

Pressure Fix

Narrow down my cause

This page lists what usually causes low water pressure whole house. The tool asks a few questions about your own system and ranks them for what you actually have, cheapest checks first. It starts with a safety screen, every time.

City or town water
Whole house
Neighbors fine
Gradual decline

Your answers come with you.No account, no email. Skip any question you cannot answer.

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Quick questions

The questions people ask next

How do I measure my own water pressure?

A screw-on gauge for an outside tap is an inexpensive hardware-store part. Attach it, open the tap fully with nothing else running, and read it. Aim for 50 to 60 PSI. Above 80 the plumbing code requires a pressure regulator, so a reading over that is worth acting on. There is no single number below which a house is broken; it depends what you are trying to run at once.

Everyone tells me it is the city. Is it?

A gradual decline is worth checking on your side first. The reverse error is the expensive one though: assuming it is a city problem when it is not, and living with it for months. Ask a neighbor; if the street is fine, look at your side.

Could my water softener be doing this?

Yes, and it is the free thing to rule out. Put it on bypass and see whether pressure returns. We sell filtration and this is still the first check we would want you to make.

My pipes are old galvanized. Does that matter?

It does. Galvanized pipe corrodes inward over decades, narrowing the bore and adding friction. That shows up exactly like a gradual decline, and no regulator adjustment will fix it.

Pages that often come up alongside this one.

These are likely causes based on what people commonly describe, a place to start, not a diagnosis, and not medical advice. For anything health-related, a certified lab test and your local health authority are the ones to trust.

Why is the water pressure low throughout my whole house?

Which of these applies?

What else it could be

A valve isn’t fully open

Leak somewhere in the system

Regulator failing or drifting

Your filter or softener is the restriction

The supply line is too small