Where the pressure adjustment lives on a well system
On most well systems, water pressure is controlled by a pressure tank and a pressure switch that work together. The pressure switch sits on top of or near the tank and has two adjustment screws — one larger screw that controls the cut-in pressure (when the pump turns on) and one smaller screw that controls the cut-out pressure (when the pump turns off). The difference between these two settings is called the pressure band, and it is usually set to 20 pounds per square inch (psi).
Before you touch anything, turn off power to the well pump at the breaker. This is not optional — you are working with pressurized equipment and live electrical connections. Write down your current pressure reading if you have a gauge on the tank, so you know where you started.
The pressure tank itself contains both water and air. Over time, the air charge inside the tank can leak out or become waterlogged, which makes the system lose pressure even if the switch settings are correct. If your pressure keeps dropping no matter what you adjust, the tank air charge may be the real problem, not the switch.
Key Takeaways
- The pressure switch has two screws: the larger one controls when the pump starts, and the smaller one controls when it stops; the difference between them should stay around 20 psi.
- Always turn off power to the pump before adjusting anything, and check your current pressure with a gauge before you make changes.
- Turning the larger screw clockwise raises the pressure at which the pump turns on; counterclockwise lowers it.
- If pressure keeps dropping after adjustment, the air charge inside the pressure tank may have leaked out and needs to be refilled with a hand pump or compressor.
- Most household wells run between 40 and 60 psi; going higher than 80 psi can damage fixtures and cause the pump to cycle too often.
Adjusting the cut-in pressure (when the pump starts)
The larger adjustment screw on the pressure switch controls the cut-in pressure — the point at which the pump turns on to refill the tank. If your water pressure is too low, you raise this screw. If it is too high, you lower it.
Use a flathead screwdriver or an adjustable wrench, depending on the switch design. Turn the screw clockwise (to the right) to raise the pressure, or counterclockwise (to the left) to lower it. Make small adjustments — a quarter turn at a time — and turn the pump back on between adjustments to see the effect. Most systems need 30 to 50 seconds to stabilize after the pump cycles, so wait before making another change.
A typical household well runs at 40 psi cut-in and 60 psi cut-out, meaning the pump turns on at 40 and shuts off at 60. If you want stronger water pressure throughout your house, raise the cut-in to 50 psi (and the cut-out will automatically move to 70 psi, keeping the 20 psi band). Do not go above 80 psi cut-out; higher pressure stresses pipes, fixtures, and the pump itself, and causes the pump to cycle on and off too frequently.
Adjusting the cut-out pressure (when the pump stops)
The smaller screw controls the cut-out pressure — the point at which the pump shuts off. In most cases, you do not adjust this screw directly. Instead, you adjust the larger screw to move both pressures together while keeping the band (the gap between them) steady at 20 psi.
If your system has a pressure band that is too wide or too narrow, you can adjust the smaller screw to change it. A wider band (say, 30 psi instead of 20) means the pump runs less often but water pressure drops more noticeably as you use water. A narrower band means the pump cycles more frequently. For most homes, 20 psi is the right balance.
If you do adjust the smaller screw, turn it clockwise to increase the band or counterclockwise to decrease it. Again, make quarter-turn adjustments and test between changes. After you finish, write down both the cut-in and cut-out pressures so you have a record if something changes later.
Testing your adjustment with a pressure gauge
You need a pressure gauge to know whether your adjustment worked. If your tank does not have a gauge permanently installed, buy a straightforward dial gauge (they cost $10 to $20 at hardware stores) and screw it onto the test port on the pressure tank or switch. The test port looks like a tire valve.
Turn the pump on and let it run until it shuts off automatically. The gauge will show the cut-out pressure — the highest pressure the system reaches. Then turn on a faucet inside the house and let water run until the pump turns back on. The gauge will show the cut-in pressure — the lowest pressure before the pump restarts.
If the cut-out pressure is higher than you want, turn off the pump and adjust the larger screw counterclockwise (a quarter turn). If the cut-in pressure is lower than you want, adjust the larger screw clockwise. Repeat the test cycle after each adjustment until you reach your target pressures.
When the pressure tank air charge is the real problem
If you adjust the switch but pressure still drops quickly or the pump cycles on and off constantly, the air inside the pressure tank has likely leaked out or been absorbed by the water. The tank needs to be recharged with compressed air.
First, turn off the pump and drain the tank completely by opening a faucet or the drain valve at the bottom of the tank. Then use a hand pump or an air compressor to add air back into the tank through the air valve (it looks like a tire valve on top of the tank). Most tanks need to be charged to about 2 psi less than your cut-in pressure — so if your cut-in is 40 psi, charge the tank to 38 psi.
After recharging, close the air valve, refill the tank by turning the pump back on, and test the pressure again with your gauge. If the pressure now holds steady and the pump cycles normally, the air charge was the problem. If pressure still drops, the tank itself may be failing and will need to be replaced.
Common mistakes that waste time and money
The most common mistake is adjusting the pressure switch without checking whether the tank air charge is still good. You can turn those screws all day and never fix a waterlogged tank. Always test with a gauge first to confirm the problem is the switch, not the tank.
Another mistake is adjusting too much at once. A half-turn or full turn of the screw can jump your pressure 10 to 20 psi. Quarter turns let you dial in the exact pressure you want without overshooting. Patience saves you from having to adjust again when ready.
A third mistake is forgetting to turn off the pump before you start. Working on a pressurized system with the pump running is dangerous and makes it harder to see what is actually happening. The pump needs to be off, and the system needs to be depressurized before you touch anything.
When to call a well contractor instead
If you have adjusted the switch, recharged the tank air, and pressure still will not hold, or if the pump will not turn on at all, the problem is likely inside the tank or the pump itself. A failed pressure switch, a leaking tank, or a worn pump are not adjustments — they are replacements.
Also call a contractor if you are not comfortable working with pressurized equipment or if you do not have a pressure gauge and do not want to buy one. A contractor can diagnose and adjust your system in one visit and will know whether the tank or pump needs to be replaced. The cost is usually $150 to $300 for a service call and adjustment.
Frequently Asked Questions
What pressure should my well system be set to?
Most household wells run between 40 and 60 psi. A cut-in of 40 psi and cut-out of 60 psi is standard. If you want stronger water pressure, you can raise both to 50 and 70 psi, but do not exceed 80 psi cut-out. Higher pressure damages fixtures and makes the pump work too hard.
How often do I need to adjust the pressure switch?
Under normal conditions, you should not need to adjust it at all. If pressure drops over weeks or months, the tank air charge is leaking out and needs to be refilled. If pressure suddenly changes, the switch may be failing. Adjustments are one-time fixes, not regular maintenance.
Can I adjust the pressure switch myself or do I need a professional?
You can adjust it yourself if you are comfortable with basic tools and can turn off the pump safely. The adjustment itself takes 15 minutes. If you are unsure about any step, or if adjustment does not solve the problem, call a contractor. A bad adjustment is usually harmless, but a pressurized tank is not a place to guess.
What does it mean if the pump keeps turning on and off?
Rapid cycling usually means the pressure band is too narrow, the tank air charge is gone, or the pump is failing. Start by checking the tank air charge with a gauge. If the air charge is low, recharge it. If cycling continues after recharging, the pump or switch likely needs to be replaced.
Is it safe to adjust the pressure switch myself?
Yes, as long as you turn off power to the pump first and do not work on the system while it is pressurized. Always depressurize by opening a faucet or drain valve before you touch the switch. If you follow those two rules, the adjustment is safe.