Low Water Pressure? Here's What's Actually Behind It
A weak shower and a weak house-wide supply have completely different causes and completely different fixes. The first step is figuring out which one you're dealing with.
Updated August 2026
Step 1: One fixture, or the whole house?
Turn on a few fixtures in different parts of the home, a bathroom sink, a shower, the kitchen faucet, and check both hot and cold water at each. If only one fixture is weak, the cause is almost always local to that fixture, a clogged aerator or showerhead, both a five-minute fix. Unscrew the aerator and rinse out the debris, or remove the showerhead and soak it in vinegar to dissolve mineral buildup.
If everything is weak, the cause sits upstream of your fixtures, before the water ever splits off to individual faucets, and that's what the rest of this page covers.
What's actually normal
Typical residential water pressure runs roughly 40 to 80 PSI. Readings below 40 PSI are generally considered low. A screw-on pressure gauge attached to an outdoor hose bib gives you a real number instead of guessing, worth the small cost if you want to confirm there's a genuine issue before calling anyone.
Step 2: Whole-house causes
- A partially closed main or meter valveThe simplest thing to check first, confirm both are fully open.
- A failing pressure regulatorMany homes have a pressure-reducing valve where the main line enters the house. When it fails, pressure usually drops evenly across every fixture at once, a plumber can confirm this by measuring pressure before and after the regulator.
- Mineral buildup in older pipesCalcium and magnesium from hard water collect along pipe walls over years, narrowing the interior gradually rather than suddenly. This connects directly to Jacksonville's own water, see our water quality guide for why hardness here is a real, common issue, not a rare complaint. This kind of buildup tends to show up as a slow decline over time rather than a sudden drop.
- A hidden leakA leak anywhere in the system diverts water and pressure away from your fixtures. Turn off every faucet and appliance, then check the water meter, if it's still moving, water is flowing somewhere it shouldn't be.
- A municipal supply issueWorth ruling out before assuming the problem is inside your own plumbing, especially if neighbors are seeing the same thing.
What to do next
A closed valve or a clogged aerator, fix it yourself. A failing regulator is usually a straightforward, contained repair. Mineral buildup severe enough to restrict flow throughout old pipes is a bigger conversation, sometimes a targeted repair, sometimes a case for whole-house repipe if the pipes themselves have narrowed beyond what cleaning can fix. A plumber with a pressure gauge can tell you which situation you're actually in rather than guessing.
Common questions
How do I know if low water pressure is one fixture or the whole house?
Turn on a few fixtures in different parts of the home, a bathroom sink, a shower, the kitchen faucet, and check both hot and cold water. If only one fixture is weak, it's almost always a clogged aerator or showerhead, a five-minute fix. If everything is weak, the cause is upstream of your fixtures, and the rest of this page is about that scenario.
What's normal water pressure for a house?
Typical residential pressure runs roughly 40 to 80 PSI, with readings below 40 PSI generally considered low. A screw-on pressure gauge attached to an outdoor hose bib gives you an actual number instead of guessing.
What causes low water pressure throughout the whole house?
The most common causes are a failing pressure regulator, a main or meter valve that isn't fully open, mineral buildup narrowing older pipes, a hidden leak, or an issue with the municipal supply itself. These all sit upstream of where the water splits to individual fixtures, which is why they affect everything at once rather than just one faucet.
How do I check for a hidden leak myself?
Turn off every faucet, appliance, and fixture in the house, then check your water meter. If it's still moving with everything off, water is flowing somewhere it shouldn't be. This is a legitimate DIY check before calling a plumber.
About the author
Ready Utilities was founded by Cedrick Reese, a retired veteran and web developer who enjoys building free, user-friendly online tools that simplify everyday tasks. He earned a Computer Systems Technician certificate from UEI College, completed Electro-Mechanical Technologies at Tulsa Welding School, and finished the Carpentry program at Florida State College at Jacksonville.