Low water pressure rarely happens overnight without warning, and it almost always has a specific cause. The first useful question is simple: is the problem at one fixture, or throughout the whole house? The answer narrows the possibilities dramatically.
Use this guide to narrow it down - and to know when it is time to call a professional for water pressure repair.
If It's Only One Fixture
A single weak faucet or shower is usually a local problem:
- A clogged aerator or screen - hard-water scale and sediment build up in the tip of the faucet or the showerhead. Soaking it in vinegar often restores flow.
- A failing cartridge - a worn cartridge in a single-handle faucet restricts flow. See our faucet repair service.
- A partially closed shut-off valve - the valve under the sink may not be fully open.
- A failing shower valve - hard-water scale and worn parts reduce flow; see our shower plumbing repair.
If It's the Whole House
When every outlet is weak, the cause is in the main supply:
- A failing pressure reducing valve (PRV) - the most common whole-house cause. The PRV regulates incoming pressure; when it fails, pressure can drop. Replacing it usually solves the problem.
- Corroded or scaled pipes - older galvanized lines close in over time. The long-term fix is often repiping or pipe repair.
- A hidden leak - a leak can steal pressure before it reaches your fixtures. See our leak detection service.
- A utility supply issue - a nearby main break or maintenance can lower pressure at the meter. Check with neighbors before calling.
What About High Pressure?
Too much pressure is just as harmful as too little. High pressure causes noisy pipes, brittle joints, dripping fixtures and premature water heater failure. If your pipes bang or you keep finding new leaks, ask us to test your pressure. Bringing it back into the 50-60 psi range protects the whole system.
Quick test: Attach a pressure gauge to an outdoor spigot. Sustained readings above 80 psi or below 40 psi are worth investigating.
How We Diagnose and Fix It
- Measure static and flowing pressure at multiple points
- Determine whether the cause is the fixture, the PRV, the pipes or the supply
- Repair or replace the failed component and verify steady pressure
Often it is a straightforward PRV replacement. When scale and corrosion are the root cause, we will explain whether a targeted repair or a whole-home repipe makes more sense.