Low Water Pressure: Causes & Fixes

First, determine if low pressure affects the whole house or specific fixtures. One fixture: the problem is localized to that fixture. One area: branch line or multiple fixture issues. Whole house: main line, valve, or supply problem. Test multiple fixtures on hot and cold—issues only with hot water point to the water heater. This diagnosis guides your next steps.

The most common cause is a clogged aerator—the screen at the faucet tip. Unscrew it, clean debris and mineral buildup, and reinstall. For showerheads, soak in vinegar overnight to dissolve mineral deposits. If cleaning doesn't help, the faucet cartridge or valve may need replacement. These are often DIY-friendly repairs with online tutorials for specific faucet models.

If low pressure affects only hot water throughout the home, the issue is likely the water heater. Check: is the inlet valve fully open? Sediment buildup can restrict flow—annual flushing helps. The dip tube may have failed, causing poor hot water delivery. Corroded pipes near the water heater can restrict flow. A plumber can diagnose water heater-related pressure issues.

Check your main shut-off valve and meter valve—partially closed valves restrict flow. Look for visible leaks that could reduce pressure. If you have a pressure regulator (bell-shaped device near the main line), it may need adjustment or replacement. Corroded galvanized pipes progressively restrict flow over years. Municipal supply issues sometimes cause temporary pressure drops—check with neighbors.

Older homes with galvanized steel pipes often experience declining pressure as corrosion narrows the pipes. This can't be fixed without replacing the pipes (repiping). Signs include: rusty water, pressure that's declined over years, visible corrosion on exposed pipes, and multiple fixture issues throughout the home. Repiping is a significant investment but permanently solves the problem.

A plumber can: measure actual water pressure (should be 40-60 PSI), inspect the pressure regulator, assess pipe condition with camera inspection, identify hidden leaks affecting pressure, and recommend solutions ranging from simple valve adjustments to repiping. If DIY checks don't reveal the cause, professional diagnosis is worthwhile before the problem worsens.