What a pressure switch does and why 60 PSI matters

A pressure switch is the device that tells your well pump when to turn on and off. It monitors the pressure inside your pressure tank and signals the pump to start filling the tank when pressure drops below a set point, then stops the pump when pressure reaches the upper limit. A 60 PSI setting means your pump will run when tank pressure falls to 40 PSI (the cut-in point) and stop when it reaches 60 PSI (the cut-out point).

Most residential well systems use a 40/60 PSI split, which balances water availability with energy use. If your switch is set too low, the pump runs constantly and wears faster. If it is set too high, you get pressure spikes that can damage fixtures and reduce water flow to upper floors or distant taps. Adjusting to 60 PSI is a straightforward task that takes about 15 minutes and requires only a flathead screwdriver.

Key Takeaways

  • The pressure switch has two adjustment screws: one for the cut-in point (when the pump starts) and one for the differential (the gap between start and stop).
  • You must turn off power to the pump at the breaker before opening the switch cover, and drain the tank to zero pressure before making any changes.
  • Turning the larger screw clockwise raises pressure; turning it counterclockwise lowers pressure, with each full turn changing pressure by roughly 2 PSI.
  • After adjustment, you must cycle the pump on and off at least twice and check the actual pressure with a gauge to confirm the setting took hold.

Locate your pressure switch and turn off power

The pressure switch is a round or rectangular box mounted on the side of your pressure tank, usually near the top. It has a cover held on by one or two bolts. Before you touch anything, locate your well pump's circuit breaker and switch it to the OFF position. This prevents the pump from starting unexpectedly while you work.

Next, drain all pressure from the tank. Open the lowest faucet in your house (usually a basement sink or outdoor spigot) and let water run until it stops. This removes the air pressure inside the tank so you can safely open the switch cover. If you skip this step, pressurized air will escape when you remove the cover and can cause injury.

Open the switch cover and identify the adjustment screws

Remove the bolt or bolts holding the cover in place and set them aside where you will not lose them. Inside, you will see a spring mechanism and two adjustment screws. The larger screw (usually labeled or marked with an "L" or arrow) controls the cut-in pressure — the point at which the pump starts. The smaller screw controls the differential, or the gap between cut-in and cut-out.

For a 40/60 PSI setting, you want the pump to start at 40 PSI and stop at 60 PSI, giving you a 20 PSI differential. If your switch is currently set to a different range, you will adjust the larger screw first to set the cut-in point, then the smaller screw to set the differential. Take a photo of the current position with your phone so you can reference it if needed.

Adjust the larger screw to set cut-in pressure

Using a flathead screwdriver, turn the larger adjustment screw. Clockwise rotation raises the cut-in pressure; counterclockwise lowers it. Each full turn typically changes pressure by about 2 PSI, though this varies slightly by switch model. If your current setting is 30/50 PSI and you want 40/60 PSI, turn the larger screw clockwise five full turns (roughly 10 PSI increase).

Do not make large adjustments in one go. Turn the screw a quarter turn, then replace the cover and turn the power back on to test. Let the pump run until it shuts off, then check the pressure gauge on the tank. Turn the power off again, drain the tank, and reopen the cover to make another small adjustment if needed. This method takes longer but prevents overshooting and damaging the switch.

Adjust the smaller screw to set the differential

Once the cut-in pressure is correct, adjust the smaller screw to set the differential — the gap between when the pump starts and stops. For a 40/60 PSI system, you want a 20 PSI gap. The smaller screw works the same way: clockwise increases the differential, counterclockwise decreases it. Each full turn changes the differential by roughly 2 PSI as well.

If your cut-in is now 40 PSI and you want cut-out at 60 PSI, you need a 20 PSI differential. Make small adjustments, test, and recheck. Many switches come pre-set to a 20 PSI differential, so you may not need to touch this screw at all if the larger screw adjustment alone gets you to the right range.

Test the adjustment and confirm with a pressure gauge

Replace the switch cover and tighten the bolts. Turn the power back on at the breaker. Open a faucet and let water run until the pump starts — you should hear it kick on. Let it run until it shuts off on its own. The pump should stop when the tank reaches 60 PSI. Repeat this cycle at least twice to confirm the setting is stable.

Use a tire pressure gauge or a dedicated water pressure gauge to verify the actual pressure. Screw the gauge onto the test port on the side of the pressure tank (it looks like a tire valve). The gauge should read close to 60 PSI when the pump shuts off, and drop to around 40 PSI when you open a faucet and the pump starts again. If the readings are off by more than 2 or 3 PSI, make another small adjustment to the larger screw and retest.

Common mistakes and how to avoid them

The most common error is adjusting the switch while the tank still has pressure in it. This can cause the cover to pop off or the spring to snap. Always drain the tank completely before opening the switch. Another mistake is making large adjustments without testing in between, which can overshoot the target and require multiple corrections.

Some people confuse the two screws and adjust the differential when they mean to adjust cut-in, or vice versa. Take a moment to identify which screw does what before you start turning. If your pressure gauge reads very differently from what the switch seems to be set for, the gauge itself may be faulty — test it on a known-good system or have it checked before assuming the switch is wrong.

Frequently Asked Questions

What if I turn the screw and nothing changes?

The screw may be stuck or the switch may be faulty. explore a small amount of penetrating oil around the screw and wait 10 minutes, then try again with gentle pressure. If it still will not turn, do not force it — you may break the internal spring. Contact a well service technician to replace the switch.

Can I adjust the pressure switch while the pump is running?

No. Always turn off power at the breaker and drain the tank first. Adjusting under pressure risks injury and can damage the switch mechanism. The only exception is checking the pressure gauge while the pump is running, which is safe and necessary to verify your adjustment.

Why does my pressure keep dropping even after I adjust the switch?

A dropping pressure usually means the tank has a leak or the bladder inside the tank has failed. The switch itself is not the problem. Have the tank inspected by a well technician. If the tank is sound, the issue may be a leaking check valve or a slow leak in the plumbing, both of which require professional repair.

Is 60 PSI the right setting for every well system?

No. Some systems use 50/70 PSI or 30/50 PSI depending on the tank size, pump capacity, and household water demand. Check your pump manual or the label on your pressure tank for the manufacturer's recommended range. If you do not have documentation, 40/60 PSI is a safe default for most residential wells.

How often should I check and adjust the pressure switch?

Check the pressure once a year as part of routine maintenance. The setting should remain stable unless the switch is faulty or the tank bladder has failed. If you notice the pump cycling on and off more frequently than usual, or if pressure fluctuates wildly, have the system inspected by a technician.