Caution! Electricity can be very dangerous, especially if you are inexperienced. Always use caution working with electricity and turn off power supply breakers when testing components or making any adjustments within the electrical system. If you are not 100% confident you can perform any of these tests safely, call a professional
The starting and stopping of a well water pump is typically controlled by a pressure switch similar to the one shown below. The switch is preset with both the cut-on and cut-off pressure and the differential is 20 PSI (pounds per square inch). The cut-on pressure is the low pressure that starts the pump and the cut-off pressure is the high pressure that turns off the pump. You may be looking to increase pressure for one of the following reasons: the preset range does not provide satisfactory pressure when the water reaches your home, your shower/faucets are lacking sufficient pressure, or your sprinkler heads require a higher pressure. Adjusting the range can be done by following a few simple steps.
Loosen the nut on top to remove the cover on your pressure switch. Factory presets can be found inside the cover of the pressure switch (as shown above). To increase or lower both cut-on and cut-off pressure you will turn the nut on top of the large center spring as seen in the picture below. Turn the nut counterclockwise to lower both cut-on and cut-off pressure or clockwise to raise both cut-on and cut-off pressure.
If you adjust your cut-on pressure you will also need to adjust the pressure tank air charge. The pressure tank should be set at 2 PSI less than the cut-on pressure.
Click here to see video: How to Check and Adjust Pressure Tanks
Click here to read blog: How to Check and Adjust Your Pressure Tank
There are very few applications where you should adjust the differential. Adjusting the differential will only adjust the cut-off pressure. Turn the differential nut counterclockwise to lower cut-off pressure or turn the nut clockwise to raise cut-off pressure.
Click on the hyperlinks below to see pressure switch videos on the RC Worst YouTube channel:
Square D Pressure Switch
Low Water Pressure Cutout Switch | Square D M4 Pressure Switch W/ Low Pressure Cut-Off
Summary and Pro Tips:
- If you adjust your cut-in pressure, you will also need to adjust the pressure tank.
- There are very few instances when the small side spring should be adjusted.
- Do not adjust the cut-off pressure too high. If the pump cannot produce enough pressure it will not shut off (and cause motor failure).
If you have further questions about your pressure switch or your water system please do not hesitate to call our experts at 855.329.4519.