First Split: One Fixture Or The Whole House?
A single weak shower is almost always local — a clogged aerator, a scaled showerhead, a failing fixture cartridge, or that fixture's supply stop half-closed. Everything weak, everywhere, is systemic. And distinguish pressure from flow: strong pressure that dies when a second fixture opens points at restricted pipe (hello, galvanized), while uniformly weak pressure points at the valve and regulator family. Two minutes of testing fixtures around the house aims the whole diagnosis.
The Usual Suspects, In Diagnostic Order
Check the obvious first: the main shutoff at the house and the valve at the meter — half-closed valves after past work are embarrassingly common. Next, the PRV (the bell-shaped regulator near where the main enters): they fail in both directions, and a failing one strangles the whole house. Then the age question: galvanized steel supply pipe corrodes shut from the inside over decades — pre-1975 Broward homes with original supply lines often have pencil-width passages inside inch-wide pipe. Last, the leak check: a spinning meter with everything off means the system is bleeding somewhere, often under the slab.
The Galvanized Story Older Broward Knows
Galvanized supply pipe was the standard before copper and PEX — and it spends its retirement rusting closed. The signature: pressure that worsened gradually over years, gets worse when multiple fixtures run, brown-tinged water after vacations, and visible corroded gray-silver pipe at the water heater or in the attic. Cleaning is not a thing; the cure is replacement — usually a whole-house repipe, which fixes pressure, water color, and the next decade in one project. Our repipe guide covers the process.
The PRV: The Cheap Fix Everyone Forgets
If your home has a pressure-reducing valve and the pressure sagged across months, the PRV is the prime suspect — they have a service life, and a failing one is a contained, modest replacement that restores the whole house. A gauge on a hose bib reads the truth in seconds: healthy residential pressure sits roughly in the 50-70 psi band. Below it with the city side fine? Regulator. Above 80 psi? Different problem — that is over-pressure, which destroys appliances and is also a PRV conversation.
When To Stop Guessing And Book The Diagnosis
You have checked the valves and the aerators, and the house is still weak: a licensed plumber with a gauge, a meter test, and eyes on your pipe material settles the question in one visit — PRV, pipe, leak, or city — with the fix priced before work begins. Two cautions worth money: a pressure complaint that earns a surprise whole-repipe quote without a gauge reading or pipe inspection deserves a second opinion, and a hidden-leak finding should come with evidence (meter movement, located position), not vibes.
Low-Pressure Suspects And Their Signatures
Match your symptom pattern to the likely cause.
| Signature | Likely cause | The fix |
|---|---|---|
| One fixture weak | Aerator, cartridge, or its supply stop | Fixture-level service |
| Whole house, gradual decline | PRV failing or galvanized corrosion | Gauge test → regulator or repipe |
| Fine until a second fixture opens | Restricted (corroded) supply pipe | Repipe conversation |
| Sudden whole-house drop | Valve, PRV failure, or main leak | Valve check → gauge → meter test |
| Meter spins with water off | Hidden leak (often slab) | Leak location, then targeted repair |
DIY Checks Before You Call
- Test several fixtures — one weak or all weak?
- Open the main shutoff and meter valve fully.
- Clean one aerator and retest that fixture.
- Hose-bib gauge if you have one: 50-70 psi is the healthy band.
- Meter moving with everything off? Stop — book the leak diagnosis.
Authoritative Sources
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Schedule ServiceFAQs
What is normal water pressure for a house?
Roughly 50 to 70 psi at a hose bib. Below about 40 feels weak everywhere; above 80 is over-pressure that shortens appliance and fixture life (and code wants a regulator). A basic gauge answers it in seconds.
Why did my water pressure drop suddenly?
Sudden drops point at valves (recently touched?), a PRV failing, a main-line leak, or municipal work. Check your valves and ask a neighbor about theirs — same problem next door means the city side; just yours means your system.
Can old pipes cause low water pressure?
Galvanized supply pipe is the classic cause — it corrodes shut internally over decades, leaving a fraction of the original passage. The signature is gradual decline plus pressure that collapses when a second fixture opens. The cure is replacement, not cleaning.
How do I know if my PRV is bad?
A gauge reading well below (or above) the 50-70 psi band with the city supply healthy points at the regulator. PRVs have a service life; replacement is a contained, modest job that frequently fixes the whole complaint.
Could low pressure mean a slab leak?
It can — a supply leak bleeds pressure and the meter spins with everything off. Warm floor spots, unexplained water bills, and the sound of running water complete the picture. Leak location comes before any concrete is touched.
Will a repipe fix my water pressure?
If corroded galvanized pipe is the cause, decisively — new PEX or copper restores full passage. If the cause is a PRV or leak, the repipe was the wrong purchase; the gauge-first diagnosis exists to keep that from happening.
