What Is a Pressure Switch?
If you rely on a private well system, the pressure switch is one of the most important components in your water setup. It tells your well pump when to turn on and off based on the pressure level in your system, keeping water flowing smoothly to your home or building.
When a pressure switch fails or is incorrectly adjusted, it can cause low water pressure, frequent cycling, or even complete system shutdown. That’s why understanding how these switches work—and how to troubleshoot them—can save you time, money, and frustration.
Common Types of Pressure Switches
Although all pressure switches serve the same basic function, there are a few key differences in design and range. Knowing which type you’re working with is the first step to proper diagnosis or replacement.
1. Standard Pressure Switch (Most Common)
These are found in many residential well systems. They typically operate in one of two pressure ranges:
- 30/50 PSI: Turns the pump on at 30 PSI and off at 50 PSI
- 40/60 PSI: Turns the pump on at 40 PSI and off at 60 PSI
The switch uses a spring-loaded diaphragm that responds to pressure changes in your pressure tank. When pressure drops to the cut-in point, it signals the pump to start. When pressure reaches the cut-off point, it shuts the pump off.
2. Low-Pressure Cut-Off Switch
This type includes a safety feature that shuts the system down if pressure drops too low—typically due to a dry well, burst pipe, or failed pump. It prevents the pump from running dry and burning out, but it needs to be manually reset before the system turns back on.
3. Adjustable Pressure Switches
Some switches allow for manual adjustment of both the cut-in and cut-out pressures. This can be useful in homes with specific water pressure needs or when working around older infrastructure. However, improper adjustments can damage your pump or tank if not done correctly.
Signs Your Pressure Switch May Be Failing
Not sure if the pressure switch is your issue? Here are some common symptoms to watch for:
- Rapid cycling (pump turning on and off frequently)
- Low or inconsistent water pressure
- No water at all
- Visible arcing or damage to switch contacts
- Burnt or corroded switch components
- Switch doesn’t click on/off as pressure changes
If you’re experiencing one or more of these symptoms, it’s worth taking a closer look at your pressure switch.
How to Troubleshoot a Pressure Switch
Before replacing anything, take these steps to diagnose the issue. Be cautious—this component is electrical, so if you’re unsure, it’s always safer to call a professional.
1. Check the Pressure Gauge
Start by looking at the pressure gauge on your tank. If the reading stays below the cut-in setting and the pump doesn’t kick on, the switch may be faulty or stuck.
2. Inspect the Electrical Contacts
Turn off power to the pump system. Remove the switch cover and look for signs of wear—such as pitting, burning, or corrosion on the contact points. Clean minor buildup with emery cloth. If contacts are severely damaged, the switch likely needs replacement.
3. Test the Diaphragm
Gently press on the lever or spring arm. If there’s no resistance or movement, the diaphragm may have failed. This internal part is not serviceable and usually means it’s time for a new switch.
4. Look for Clogged Tubing or Ports
Sediment buildup inside the pressure switch’s small port or the tubing connected to it can prevent accurate readings. Remove the switch and check for blockages. Clean out debris carefully using a small wire or compressed air.
5. Reset the Low-Pressure Cut-Off (If Applicable)
If you have a low-pressure cut-off switch and the system shut down, lift the lever or hold it in the reset position while the pressure builds back up. If pressure doesn’t return, the issue may lie with the pump, power supply, or piping.
When to Replace the Pressure Switch
Pressure switches are relatively inexpensive and easy to replace. If you’ve cleaned the contacts, checked for blockages, and the switch still doesn’t engage correctly, replacement is likely your best option.
At Petersheim, we typically recommend replacing rather than trying to repair a failing switch—especially if the system is older or if the switch has visible damage. We also ensure the new switch is compatible with your system’s PSI settings and tank size.
Can You Adjust a Pressure Switch Yourself?
Yes—but with caution. Most standard pressure switches have two adjustment nuts:
- Large nut: Adjusts both cut-in and cut-out pressure
- Small nut: Adjusts the differential between cut-in and cut-out
Only make small adjustments at a time, and always test the system afterward. Over-adjusting can stress the pump or cause water hammer (banging pipes). If you’re not comfortable adjusting your switch, give us a call—we’re happy to help.
Don’t Ignore the Signs
Ignoring a faulty pressure switch can lead to bigger problems, including pump burnout, loss of water, or damage to pipes and fittings. Early troubleshooting saves time and helps maintain reliable water flow.
If you notice inconsistent pressure or suspect your system isn’t operating as it should, let us take a look. Whether it’s replacing a worn switch, upgrading your control setup, or testing the entire system, Petersheim has the tools and expertise to keep your water running smoothly, contact us today.