Low water pressure is one of the most common plumbing complaints we hear — especially in homes with private wells. Here are the seven most likely causes and what to do about each one.
1. Waterlogged Pressure Tank
For homes on well water, this is the single most common cause of low or fluctuating water pressure. A pressure tank contains a bladder that separates water from pressurized air. When that bladder fails, the tank fills with water and can no longer maintain steady pressure — you'll notice pressure that starts strong and quickly drops off. Replacing a pressure tank typically costs $400–$800 installed and immediately restores normal pressure.
2. Failing Well Pump
A well pump that's losing efficiency will produce lower pressure over time. This is especially common in pumps over 10 years old. You may also notice the pump running longer than usual to maintain pressure. If pressure loss is gradual over months, suspect the pump. A pump diagnostic test can determine if the pump is producing its rated flow and pressure — if not, replacement is likely needed.
3. Clogged or Corroded Pipes
In older homes with galvanized steel pipes, corrosion buildup inside the pipes progressively narrows the water flow over years. The result is declining pressure throughout the house that worsens over time. If your home was built before 1980 and has original plumbing, corroded galvanized pipes are a likely culprit. Repipe with copper or PEX is the long-term solution.
4. Partially Closed Shutoff Valve
This sounds obvious, but it's surprisingly common: a shutoff valve that wasn't fully reopened after plumbing work. Check the main shutoff valve near your pressure tank or meter and make sure it's fully open (lever parallel to the pipe, or multi-turn valve turned all the way counterclockwise).
5. Pressure Regulator Failure
Homes on municipal water typically have a pressure regulator (or pressure reducing valve, PRV) where the water line enters the house. These valves last 10–15 years and can fail, causing either very low or very high pressure. A failing PRV is often the culprit when pressure suddenly drops throughout the house on a city water connection. Replacement costs $200–$500 installed.
6. Clogged Aerators or Showerheads
If low pressure is isolated to one faucet or fixture, the issue is almost certainly a clogged aerator or showerhead. Mineral deposits (especially in hard water areas of Maryland) accumulate in the small screens and restrict flow. Unscrew the aerator and soak it in white vinegar for an hour — this often fully resolves single-fixture pressure issues at zero cost.
7. Low Well Water Table
During extended dry periods or drought, the water table can drop below the pump's intake level. This causes intermittent pressure loss, air in the lines, and in severe cases, a dry pump (which can burn out the motor quickly). If pressure loss is seasonal and coincides with dry weather, this may be the cause. Solutions range from lowering the pump to drilling deeper — a licensed well driller should evaluate.
Most water pressure problems are diagnosable and fixable without major expense — if you catch them early. If you're experiencing low pressure across your home in Maryland, Delaware, or Pennsylvania, call Milloway Pipeworks for a free assessment. We'll identify the cause and give you a straightforward repair recommendation. (443) 945-3186.