What Causes Low Water Pressure in a Well System?
What Causes Low Water Pressure in a Well System — Deep Dive Plumbing Maryland
Low water pressure from a well system has eight common causes — and the fix is completely different depending on which one you have. Here's how to figure out what's going on.
8 Causes of Low Well Water Pressure
Failing Well Pump
A well pump that's losing efficiency delivers less water at lower pressure. As the pump motor wears, it can no longer maintain the flow rate it was designed for. If your pressure has been gradually declining over months, a failing pump is the most likely cause.
Waterlogged Pressure Tank
A pressure tank with a failed bladder can't maintain a steady pressure buffer. You'll notice pressure that fluctuates wildly — surging when the pump kicks on, then dropping quickly. The pump will also short-cycle (turn on and off every 30 seconds).
Pressure Switch Set Too Low
The pressure switch controls when your pump turns on and off. If it's set to a low range (20/40 PSI instead of 40/60 PSI), your system will operate at lower pressure. This is an easy adjustment — but it should only be changed if the pump and tank can support higher pressure.
Clogged Well Screen or Pump Intake
The well screen at the bottom of the casing prevents sand and sediment from entering the pump. Over time, iron deposits and sediment can clog the screen, restricting water flow to the pump. This is common in Maryland wells with high iron content.
Mineral Buildup in Pipes
Hard water deposits calcium and magnesium scale inside pipes, gradually reducing the internal diameter. Galvanized steel pipes are especially prone to this — a 3/4-inch pipe can be reduced to 1/4-inch effective diameter after 20–30 years of hard water.
Partially Closed Shut-Off Valve
A partially closed main shut-off valve or pressure tank bypass valve restricts flow throughout the house. Check that all valves in your system are fully open.
Low Well Yield
If your well can't produce water fast enough to meet demand, pressure drops when multiple fixtures run simultaneously. This is a well capacity issue, not a pump issue — and it requires a different solution (Cycle Stop Valve, storage tank, or demand management).
Leak in the System
A leak in the pressure tank, pump discharge line, or buried water line bleeds pressure from the system. If your pump runs constantly but pressure is low, a leak is a likely cause.
How to Diagnose Low Pressure Yourself
Low Water Pressure in Maryland Well Systems
In Calvert County and Anne Arundel County, the most common causes of low well water pressure are waterlogged pressure tanks and failing well pumps — in that order. The high iron content in local well water accelerates both problems: iron deposits on the pressure tank bladder (causing early failure) and on the pump impellers (reducing efficiency).
If you have low pressure and your system is more than 8 years old, a professional diagnosis is the fastest path to a solution. We can test your pump performance, check the pressure tank, and inspect the pressure switch in a single visit.