Low pressure from a well is almost always traceable to one of five causes. Start from the cheapest and easiest before calling a well company. Most residential well pressure complaints resolve without a pump replacement.
Cause 1: Clogged Sediment Filter
This is the most overlooked cause. If you have a whole-house sediment filter at the pressure tank, a clogged cartridge creates a measurable pressure drop across the housing. A filter that was installed and forgotten can restrict flow significantly.
When did you last replace it?
Filter cartridges become invisible once installed. They keep doing their job until they do it too well and start blocking flow. Replace the cartridge first, run the system for a few minutes, and check pressure. If that fixes it, you found the cheapest possible solution.
Cause 2: Waterlogged Pressure Tank
The pressure tank has an internal bladder that maintains air pressure. The air cushion is what keeps pressure stable between pump cycles. If the bladder fails, water fills the entire tank and the air cushion disappears.
The result: the pump cycles on and off very rapidly, sometimes every few seconds, and pressure drops to almost nothing between cycles. Rapid pump cycling is the clearest sign of a waterlogged tank.
How to test it: Turn off the pump and release pressure from the system. Locate the Schrader valve on top of the pressure tank (it looks like a tire valve stem). Press the pin in the center. If air comes out: tank is fine. If water comes out: bladder has failed.
Pressure tank replacement: $150-400 for the tank, $200-400 for labor if you hire it out. It’s a DIY repair if you’re comfortable with basic plumbing.
Cause 3: Incorrect Pressure Switch Settings
The pressure switch controls when the pump turns on (cut-in) and when it shuts off (cut-off). Standard residential settings are 30/50 psi or 40/60 psi. If the switch is set too low, or if the contacts inside are corroded, you get lower pressure than you should.
You can check and adjust a pressure switch yourself, but it involves working near live electrical components at the pressure tank. If you’re not comfortable with that, have a plumber or well service company do it. The adjustment itself takes 5 minutes.
A corroded switch is common in areas with humid well houses or basements. Replacement switches run $15-30.
Cause 4: Failing Well Pump
Pump performance degrades over time. The impellers that move water wear down after years of use. A pump that produced 10 gpm when installed might produce 5-6 gpm after 10-15 years.
The signs of pump degradation are gradual: pressure loss that develops over months rather than appearing overnight, the pump running for longer periods to reach cut-off pressure, and occasionally air sputtering from faucets as the pump struggles to maintain prime.
Pump replacement is the major job. Cost ranges from $1,500 to $4,000 or more depending on well depth and pump type. Submersible pumps (the most common type in deeper wells) require pulling the drop pipe and pump from the well casing.
Don’t assume you need a new pump until you’ve ruled out the sediment filter and pressure tank. Those two causes are far more common and far less expensive.
Cause 5: Low Water Table
The water table fluctuates seasonally. In drought years or in late summer, shallow wells can experience a temporary drop in yield. The pump is still working fine, but there’s simply less water to move.
Check with your county well database or ask neighbors with wells. If multiple wells in your immediate area are showing low pressure at the same time, it’s likely a water table issue, not a mechanical one. This typically resolves with seasonal rainfall.
A well contractor can measure your static water level and compare it to the original well completion report. If the table has permanently dropped, you may need the well deepened or a new well.
Bonus Cause: Scale Buildup in Older Pipes
In hard water areas with older galvanized steel pipe, scale accumulates inside the pipe over years and decades. The effective internal diameter shrinks. Pressure appears low everywhere but is especially bad in older sections of the house or at the end of long pipe runs.
This isn’t a well problem. It’s a plumbing problem. The fix is repiping with PEX or copper. If you have galvanized pipe and your well and tank check out fine, check the pipe diameter at an accessible connection point. Heavy white or orange scale buildup inside the pipe is visible when you cut it.
How to Diagnose Yours
Work through this in order:
- Replace the sediment filter cartridge. Test pressure. If better: done.
- Check the pressure tank Schrader valve with the pump off and pressure at zero. Water at the valve means a failed bladder. Rapid pump cycling also points here.
- Look at your pressure gauge and watch the pump. Consistent 30/50 or 40/60 readings with normal cycling: switch and tank are fine.
- If none of the above apply, a well contractor’s diagnostic visit ($75-150) is worth the cost. They can measure pump output and confirm whether performance has degraded before you commit to replacement.
Replacing the sediment filter and pressure tank covers the majority of residential well pressure complaints and costs well under $500 combined. Start there.