What Causes Low or High Water Pressure in a Home?
Low water pressure can come from a partially closed valve, clogged fixture, pressure-regulator problem, leak, restricted piping, private well/pressure-system issue, or utility-side problem. High pressure can come from excessive supply pressure or a failed/missing pressure-reducing valve. The first diagnostic step is deciding whether the problem affects one fixture or the whole property.
Water-pressure complaints are often described as one problem, but pressure and flow are not exactly the same thing. A clogged faucet aerator can make one sink feel weak even when building pressure is normal.
Low/high pressure quick diagnosis
Pressure vs. flow: why the difference matters
Pressure is the force available in the water system. Flow is the amount of water moving through a fixture or pipe. A restriction can reduce flow without changing the static pressure at the service entrance — a clogged aerator lowers fixture flow, while a failed regulator affects the whole building.
Common causes of low water pressure
One fixture only
- Aerator
- Showerhead
- Cartridge
- Stop valve
- Flexible connector
Whole property
- Main shutoff not fully open
- Pressure-reducing valve problem
- Private service restriction
- Active leak
- Utility-side low pressure
- Well pump or pressure-tank problem
Common causes of high water pressure
Current Florida residential code states static water pressure should not exceed 80 psi and requires an approved pressure-reducing valve when main pressure exceeds that level. High pressure can result from high public supply pressure without adequate regulation, a failed regulator, or thermal expansion in a closed system.
How can you check water pressure?
A pressure gauge connected to a suitable hose bib can provide a direct static reading. Make sure fixtures are not actively using water when checking, and don’t diagnose a regulator failure from one fixture’s flow alone.
What if the home has a private well?
Private-well pressure is controlled by a pump/pressure system rather than only a municipal supply. Problems can involve the pressure switch, pressure tank, pump, well yield, or private piping.
When to call a plumber
- Whole-house pressure is persistently low
- Static pressure is excessive
- The regulator may have failed
- A leak or piping restriction is suspected
Frequently asked questions
What is the maximum residential water pressure in Florida?
The 2023 Florida Residential Code states static water pressure should not exceed 80 psi; a pressure-reducing valve is required above that.
Why is only one faucet low pressure?
A local aerator, cartridge, stop valve, or connector is more likely than a whole-house problem.
Why is my whole house suddenly low pressure?
Check for utility issues, main-valve position, a large leak, regulator problem, or well-system problem.
Can a water leak cause low pressure?
Yes, especially a significant supply leak.
Can old pipes cause low flow?
Yes, internal corrosion/restriction can reduce available flow.
Is high water pressure bad for plumbing?
Excessive static pressure increases stress on fixtures, valves, and hoses.
Can I adjust my pressure regulator myself?
Minor adjustment is technically possible on some models, but measuring actual pressure matters — service is safer if the regulator has failed.
Why does pressure change on a private well?
Well systems intentionally cycle within a range, but abnormal swings can indicate pump or tank issues.
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