Plumbing service
Water pressure problems
Short answer
Low pressure at a single fixture usually means a clogged aerator, showerhead or cartridge. Low pressure throughout the house points to a partly closed main valve, a failing pressure-reducing valve, corroded pipe, a leak, or the water supply itself. Pressure that's too high is also a problem: it strains pipes and appliances, and plumbing codes generally cap residential pressure at 80 psi.
Updated · Editorial team; not yet technically reviewed
Water Pressure Problems at a glance
- Normal range
- Commonly about 40–80 psi for a home.
- Measure it
- A hose-bib pressure gauge from a hardware store gives a reading in seconds.
- One fixture
- Aerator, showerhead, cartridge, or a partly closed fixture valve.
- Whole house
- Main valve, pressure-reducing valve (PRV), corroded pipe, leak, or the utility supply.
Narrowing it down
Is it one fixture or all?
Check several faucets, hot and cold. Hot only points to the water heater or its valves.
Clean the aerator or showerhead
Unscrew it and rinse out debris and scale. This fixes many single-fixture complaints.
Check the valves
Make sure the main shutoff and the fixture's supply valves are fully open, especially after recent work.
Measure static pressure
Screw a gauge onto an outdoor faucet with everything else off. Compare to the 40–80 psi range.
Ask the neighbors or utility
If others are affected, the cause may be the public supply, which your utility handles.
Causes and fixes
| Cause | Clue | Fix |
|---|---|---|
| Failing PRV | Pressure dropped or spiked over time; a bell-shaped valve near the main | Adjust or replace the valve |
| Corroded galvanized pipe | Older home, gradual decline, rusty water | Section replacement or repiping |
| Hidden leak | Meter moves with everything off | Leak detection |
| Undersized or long service line | Worse when two fixtures run | Upsizing the line |
| High pressure (over 80 psi) | Banging pipes, dripping T&P valve, running toilets | Install or replace a PRV; add an expansion tank |
Homes on private wells
On a well, pressure comes from the pump and pressure tank, not the utility. Pressure that cycles up and down quickly, or drops sharply during use, often points to the pressure tank's air charge, the pressure switch, or the pump. See well pump repair.
What affects the cost
- Diagnosis and pressure testing
- PRV adjustment vs. replacement, and whether the valve is easy to reach
- Adding an expansion tank when a PRV creates a closed system
- Replacing corroded sections vs. repiping
- Any service line work between the meter and the house
We don't publish prices; they vary by market. Get a written quote first.
Problems that lead to water pressure problems
Common questions
Why did my water pressure suddenly drop?
A sudden whole-house drop can come from a utility main break or work nearby, a partly closed valve, a failed pressure-reducing valve, or a major leak. Check with neighbors and your utility, then check the meter for a leak.
What is normal household water pressure?
Roughly 40–80 psi. Many plumbing codes require a pressure-reducing valve when street pressure exceeds 80 psi.
Why is my water pressure low only in the shower?
Usually a clogged showerhead or a failing shower valve cartridge or pressure-balancing spool.