Low Water Pressure in the House: Common Causes
Low pressure may affect one fixture or the whole house, and that distinction helps narrow the cause quickly.
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Before you startUse only the checks you can perform safely. Disconnect power before homeowner-serviceable cleaning or inspection. Stop when a repair involves gas, exposed wiring, high voltage, a roof, structural components, or anything outside your experience.
Common signs
- Weak shower flow
- Faucets fill slowly
- Pressure changed suddenly
Most likely causes
1. Clogged aerator or showerhead
Mineral deposits can restrict a single fixture.
2. Partially closed shutoff valve
A valve may have been left partly closed after service.
3. Pressure regulator issue
Homes with regulators can lose pressure when the regulator fails.
4. Leak or supply problem
A hidden leak or utility-side issue can reduce pressure throughout the home.
Safe checks to try first
- Compare pressure at several fixtures to see whether the issue is local or whole-house.
- Clean a faucet aerator or showerhead with mineral buildup.
- Verify accessible main and fixture shutoff valves are fully open.
- Check for unexplained water-meter movement when all fixtures are off.
When to call a professional
Call a plumber for suspected hidden leaks, regulator failure, corroded piping, or persistent whole-house pressure loss.
Bottom line
Start with the simplest visible cause, change one thing at a time, and avoid repeated resets or disassembly when a safety device keeps tripping. A recurring problem usually deserves a proper diagnosis rather than a temporary workaround.