Low water pressure in the house: causes and fixes
Quick answer
The fastest way to diagnose low water pressure is to figure out the scope: one fixture, or the whole house? A single slow faucet or showerhead is usually a clogged aerator or mineral buildup you can clean in minutes. Low pressure everywhere points to a partly closed main valve, a failing pressure regulator (PRV), corroded pipes, or a municipal/well supply issue. Note whether it affects hot, cold, or both — hot-only problems often trace back to the water heater.
Common causes
- Clogged aerators or showerheads from mineral and sediment buildup (single-fixture problems).
- A partially closed main shutoff or water-meter valve.
- A failing pressure-reducing valve (PRV) where the main enters the house.
- Corroded or scaled galvanized pipes in older homes, narrowing over time.
- A municipal supply issue, or for wells, a pressure-tank or pump problem.
- A hidden leak bleeding off pressure (watch for a meter that spins with everything off).
What to check first
- Is it one fixture or the whole house? Test several taps to narrow it down.
- Does it affect hot, cold, or both? Hot-only points toward the water heater or its shutoff.
- Unscrew and clean aerators and showerheads — soak them in vinegar to dissolve mineral buildup.
- Confirm the main shutoff and meter valve are fully open.
- Ask a neighbor if their pressure dropped too (a clue it's the municipal supply).
When it's urgent
A sudden, whole-house loss of pressure can signal a burst or leaking main. If you see wet spots in the yard or basement, hear running water with everything off, or the meter keeps spinning, shut off the main and call a plumber — a hidden leak can cause major damage and a high bill.
DIY vs. call a pro
You can likely DIY
- Cleaning or replacing clogged aerators and showerheads.
- Descaling fixtures with vinegar.
- Confirming shutoff valves are fully open.
Call a pro for
- Testing and replacing a failed pressure-reducing valve.
- Diagnosing and repiping corroded galvanized lines.
- Finding hidden leaks, and well pump or pressure-tank problems.
Estimated cost range
How HouseCue helps
HouseCue is a private, homeowner-first app that turns this from a one-time worry into a tracked plan. Snap a photo for an AI diagnosis, upload your inspection report to auto-build a handbook, and get seasonal reminders for your roof, HVAC, water heater, plumbing, and electrical — so nothing slips. Connecting with a pro is always optional and only when you choose.
Get started freeFrequently asked questions
Why did my water pressure suddenly drop?
A sudden drop across the whole house often means a partly closed valve, a failed pressure regulator, or a leak/main break. Check that your main and meter valves are fully open first; if pressure is still low and you suspect a leak, shut off the main and call a plumber.
Why is only my hot water pressure low?
Hot-only low pressure usually traces to the water heater — sediment buildup, a partly closed shutoff on the heater, or scaling in the hot lines. Flushing the tank and checking the heater's shutoff valve are good first steps.
What is a pressure-reducing valve?
A PRV is a valve where the municipal main enters your home that lowers incoming street pressure to a safe household level. When it fails, it can cause low (or sometimes high) pressure throughout the house and usually needs professional replacement.
Related guides
HouseCue guides are general educational information, not professional inspection, engineering, or contracting advice. Costs vary by market. For safety issues — gas, electrical, structural, or major water — contact a qualified professional.