Low water pressure is frustrating — weak showers, slow-filling appliances, and reduced performance from every faucet. But it's also a signal. Low pressure is rarely a standalone problem; it usually points to an underlying issue in your plumbing system that deserves investigation. Here are the most common causes and what can be done about each one.
Partially Closed Shutoff Valves
The simplest explanation is often the right one. Check both the main water shutoff valve (usually near the water meter or where the main line enters the house) and the secondary shutoff valve (often near the water heater). If either has been partially closed — perhaps after recent plumbing work — it will restrict flow throughout the home. Both should be fully open.
Pressure Regulator Issues
Many homes have a water pressure regulator (also called a pressure reducing valve or PRV) installed where the main line enters the home. This device is designed to maintain safe, consistent pressure. When it fails or wears out, it can cause either abnormally high or abnormally low pressure throughout the home. A plumber can test and replace a faulty PRV.
Mineral Buildup and Scale in Pipes
In areas with hard water — like Escondido — mineral deposits can accumulate inside pipes over years, gradually reducing the interior diameter and restricting flow. This is especially common in older galvanized steel pipes and in fixtures, aerators, and showerheads. Cleaning or replacing affected fixtures can help; in severe cases, repiping affected sections may be the long-term solution.
Leaks in the Supply Line
A hidden leak in a supply line diverts water away from its intended destination, reducing pressure at fixtures. If you notice pressure drops alongside higher water bills or unexplained damp spots, a leak should be ruled out as a contributing factor. Professional leak detection can identify and locate supply line leaks accurately.
Municipal Supply Issues
Occasionally, low pressure is caused by issues with the municipal water supply — peak demand periods, main breaks, or supply pressure changes. If neighbors are experiencing the same issue simultaneously, contact your water utility. If it's isolated to your property, the cause is likely within your plumbing system.
Corroded or Aging Pipes
In homes with older galvanized steel plumbing, corrosion can significantly reduce interior pipe diameter over time, cutting available water pressure. If your home has original galvanized pipes and persistent low pressure, a plumbing inspection may reveal whether a targeted repipe would restore full performance.