Low water pressure has a handful of common causes, ranging from a five-minute fix to a sign of a bigger issue underneath your home. Here's how to tell the difference.
Start with one fixture or the whole house
The first useful question is whether low pressure affects one fixture or every tap in the house. A single weak faucet usually points to something local, like a clogged aerator or a worn cartridge. Pressure that's low everywhere points to something further upstream — your main line, pressure regulator, or aging pipe.
Common culprits, from simple to serious
Mineral buildup in an aerator or showerhead is the easiest fix — a quick clean or soak often restores flow immediately. A partially closed shut-off valve is another simple check. On the more serious end, corroded galvanized pipe narrows from the inside over years, and a failing pressure regulator can drop pressure house-wide.
Do
- Unscrew and clean the aerator on a single weak faucet first
- Check that your main shut-off valve is fully open
- Compare pressure between a couple of different fixtures to narrow down the cause
- Check with neighbors if pressure issues seem sudden — it could be a municipal supply issue
Don't
- Don't assume it's always the city's fault before checking your own fixtures and valves
- Don't ignore house-wide low pressure that's gradually gotten worse over months or years
- Don't keep replacing fixtures without addressing pressure issues at the source
Quick tip: If pressure has dropped gradually over months or years rather than suddenly, it's often a sign of narrowing pipes rather than a single fixable part — worth having a plumber take a look.