Why is my well water pressure dropping?
Updated August 2026
Well pressure that slowly fades over weeks is most often a waterlogged pressure tank that has lost its air charge, or a clogged sediment filter choking the flow, not a dying pump. Both are cheap fixes next to a pump replacement. A healthy system snaps the pump on at a cut-in pressure and off at a cut-out, commonly 40 and 60 psi, and holds that range steadily. When the tank floods or the switch drifts, the pump short-cycles and pressure sags at the tap. Rule out the tank, the filter, and the switch before anyone talks you into pulling the pump.
Safety first: well pumps and their pressure switches run on 240-volt circuits, and a submersible sits at the end of a long drop pipe you cannot safely lift alone. Always cut power at the breaker before you open the pressure switch or pump-control box, and leave pulling a submersible to a well contractor with the right rig. If the water suddenly turns cloudy or gritty along with the pressure drop, stop drinking it and have the well tested before you troubleshoot further.
Causes, most likely first
| Cause | How likely | The fix | Typical cost |
|---|---|---|---|
| Clogged sediment filter or intake screen | Most common | Swap the filter cartridge and clean the screen; put it on a schedule if your water carries grit. | $10–30 |
| Waterlogged pressure tank (lost air charge) | Common | Recharge the tank to 2 psi below cut-in, or replace a tank with a ruptured bladder. | $0, or $200–500 replaced |
| Misadjusted or worn pressure switch | Common | Reset the cut-in/cut-out (often 40/60 psi) or replace a pitted switch. | $20–60 |
| Slowly failing pump or worn impellers | Occasional | A contractor measures amp draw and drawdown, then replaces the pump if it is weak. | $400–1,500+ |
| Dropping water table | Occasional | Lower the pump or spread out peak usage during dry spells. | Varies |
| Leak in the supply or drop line | Rare | Trace and repair the leaking pipe or fitting. | $150–800 |
Check these first
- Read the gauge at the pressure tank and watch a full cycle; note the pressure where the pump kicks on and where it shuts off.
- Rap your knuckles up and down the tank; a hollow ring near the top over a dull, water-heavy bottom is normal, while a tank that sounds full of water all the way up is waterlogged.
- Replace the sediment filter cartridge, the single most common cause of gradual pressure loss and the cheapest to rule out.
- With the power off and the system drained, put a tire gauge on the tank's air valve; it should read about 2 psi below the pump cut-in.
- Listen for rapid pump cycling, snapping on and off every few seconds, the classic signature of a failed tank rather than a bad pump.
Prevent it next time
Gradual pressure loss is the kind of problem a small habit heads off. Change the sediment filter on schedule, keep an eye on the gauge, and test the well pump and its pressure once or twice a year so a drifting switch or a softening tank shows up early. Check the tank's air charge annually while you are at it. Knowing the typical well pump lifespan of 8 to 15 years lets you plan a replacement on your terms, and our well pump maintenance checklist keeps the tank, switch, and filter on a routine.
When to call a pro
Filter swaps, tank air-charge checks, and switch adjustments are all reasonable DIY, and a new pressure switch is a $20 to 60 part. Bring in a licensed well contractor when the tank needs replacing ($200–500), when amp and drawdown tests point to a tired pump, or when pulling and replacing a submersible is on the table at $800 to 2,500. Call sooner if pressure loss comes with sputtering air at the taps or sand in the water, since those hint at a dropping water level or a cracked drop pipe rather than a simple tank problem.
Most of the causes above are maintenance problems wearing a disguise. OnOtto keeps the boring prevention on schedule so the 2 a.m. version doesn't happen.
Stop chasing symptoms, free for 30 daysFrequently asked questions
How do I know if my well pressure tank is bad?
The tell-tale sign is rapid pump cycling: the pump snapping on and off every few seconds instead of running in longer, steady cycles. A good tank holds a cushion of air that lets the pump rest between draws; when the bladder fails and the tank waterlogs, that cushion is gone and the pump hunts constantly. You can also tap the tank (hollow up top, solid with water below is healthy) or check the air charge with a tire gauge, which should sit about 2 psi under the cut-in pressure. A waterlogged tank runs $200 to 500 to replace.
What should my well pressure switch be set to?
Most residential systems use a 40/60 switch, meaning the pump cuts in at 40 psi and cuts out at 60. Some run 30/50 or 50/70 depending on the home and pump. Whatever the pair, the two numbers should stay 20 psi apart, and the pressure tank's air charge should be set 2 psi below the cut-in, so 38 psi for a 40/60 setup. If pressure sags low before the pump kicks on, the cut-in may have drifted down; a $20 to 60 switch and careful adjustment usually restores it.
Why does my well pump short cycle?
Short cycling, where the pump rapidly clicks on and off, is almost always a pressure tank that has lost its air charge. Without that air cushion, even a small draw sends the pressure straight past the cut-out and right back to cut-in, so the pump can never settle. Left alone, the constant starting wears the motor and can burn it out years early. Recharging the tank's air to 2 psi below cut-in fixes it if the bladder is intact; a ruptured bladder means a $200 to 500 tank replacement.