603.868.3212    |              |    Emergency Service

Well Water Pressure Switch

Well Water Pressure Switch

Each water system is unique and has different needs. Please contact our office at 603-868-3212 with specific questions about your water delivery and filtration system. 

If you live on a property with a well you may have a water delivery system that utilizes a pressure switch to regulate when your well pump turns on and off. 

This article will go over:

  • What is a Well Water Pressure Switch?
  • How does it work?
  • What is a Low Water Cut Off Switch?
  • Troubleshooting a Low Water Cut Off switch
  • Basic maintenance

What is a well water pressure switch?

A pressure switch is a mechanical component most commonly found at the tank tee of the pressure tank. This switch senses pressure in your home’s plumbing system by utilizing a small diaphragm and spring system that causes the switch to turn the well pump on and off. These switches can be set to different cut in/off pressure readings depending on the system design. Most commonly we see pressure switches set to a 30/50 psi or 40/60 psi pressure cycle.

Pressure tank with complete tank tee utilizing a pressure switch.

How does a well water pressure switch work?

Once the water pressure drops to the cut in pressure (Commonly, 30 psi – 40 psi), the switch will engage and cause the contacts in the switch to close, completing the connection from the electricity in your home to the well pump. This engagement is what allows for your well pump to kick on and send water to the pressure tank. 

At this point in the cycle, the contacts will stay open until the pressure switch reaches its shut off pressure (Commonly, 50 psi – 60 psi). If you are using a large amount of water, your well pump may not be able to achieve shut off pressure while you are using water. In this instance you will be at the mercy of how much water your well and your pump can deliver. If you are using a small amount of water, your pump may be able to achieve that shut off pressure because the amount of water the system is able to deliver exceeds the amount of water being used at that given time. 

Once you stop using water, the system will deliver water to the pressure tank until it reaches the cut off pressure (Commonly, 50 psi – 60 psi) and the system will remain at that pressure until water is used again. 

This cyclical pattern of drawing the water in the pressure tank down to the cut on pressure and filling it up to the cut off pressure is what’s happening as you use water throughout the day. 

This technology is not very sophisticated but it gets the job done. If you’d like to learn about our systems that utilize a pressure sensor, and are more robust, give us a call at 603-868-3212 or take a look at our blog post about Constant Pressure Systems!

What is a Low Water Cut Off switch?

A low water cut off switch is a specific type of switch that cuts power off to the pump once the system drops below the desired cut on pressure. It is recognizable because the switch has a lever on its side which is used to force the contacts together when the switch has tripped. The reason for this design is to keep the well pump or jet pump from running constantly if the water level drops below the pump or if the pump is unable to provide enough force to deliver water to the home. This can save the pump from burning out and can prevent unnecessary use of electricity. 

Low Water Cut Off Switch

Troubleshooting a Low Water Cut Off switch.

Let’s say you have been doing a lot of lawn watering and all of a sudden you have no water. 

  • First see if you have a low water cut off switch. You’ll be able to tell this if you see a lever on the side of the switch. 
  • If you do, turn your pump off at the breaker and let the well rest for an hour or two. 
  • After an hour or two, turn the well pump breaker back on, and then turn the lever at the pressure switch to the start position. Turning the lever will force the contacts together, sending electricity to the pump. 
  • You may need to hold it in the start position for a couple of seconds until enough water pressure is sent to the pressure tank to prevent the switch from tripping again. 
  • Use water sparingly for the rest of the day. This will give the well a chance to recover.

If water does not return to the home, you may need to let the well rest for a longer period of time or the problem may not be somewhere else in the water delivery system. Give us a call at 603-868-3212 and we can talk you through some more out of water troubleshooting. 

Basic maintenance

It is important to have a functioning pressure switch because it is the brain of your water delivery systems. It is important to note that there is live electricity within the switch. Shut off power to the well pump before interacting with the pressure switch.  

-The switch should not show any major signs of corrosion or charring around the contacts.

-The contacts should have adequate spacing between each other when in the open position. Over time, components can loosen and contacts can get closer together causing arcing when in the open position. This can be a potential fire hazard. 

-Perhaps the biggest piece of advice is to confirm that you have adequate air pressure in your pressure tank. The pressure tank, when empty, should have a psi reading that is roughly 2 psi below the cut in pressure pressure ( Commonly 28 – 38 psi). After turning power off to the well pump, you can take the cover off of your pressure switch (Danger! Live electricity within the switch if power is not turned off) you’ll be able to see the cut in and cut out pressure labeled inside of the switch. If a pressure tank has inadequate air pressure or fails, then it can cause short cycling which can then burn out a pressure switch and/or burn up the well pump. 

This technology is not very sophisticated but it gets the job done. If you’d like to learn about our systems that utilize a pressure sensor, and are more robust, give us a call at 603-868-3212 or take a look at our blog post about Constant Pressure Systems!

Each water system and family has different needs to please feel free to call us at 603-868-3212 with any questions about pressure tanks, water supply, or water treatment.