Basically, a water pressure control switch serves to regulate the water supply inside the home. When the water pressure plunges to a certain level, the control switch detects the need for more water, and spring-loaded electric components make contact, switching on the pressure pump. Likewise, when the pressure is restored to a set level and the water tank is filled to capacity, the electric components disengage, and the pressure pump switches off. No special apparatus are needed to fine-tune a water pressure control knob. Ordinary homeowners can carry out the task using a pair of pliers.
Switch off the power and take out the switch casing
To start with, unplug or disconnect the pressure pump from the power source to avoid the risk of electrocution. With the use of a pair of pliers, loosen the nut that clasps the protective casing in place. Lift the casing off the pressure control switch mechanism. You will notice two springs fastened by adjustment nuts which act as the control for the pressure control switch. Note that these are the control switches that you will be adjusting.
Adjust the pressure setting on the switch
The adjustment nut that is positioned on the larger spring serves to adjust the pressure. To increase the working pressure of the water pump, you only need to rotate the nut in a clockwise direction. On the other hand, the smaller spring and adjustment nut regulates the cut-off pressure of the water pump. By turning the nut stationed on the smaller spring in a clockwise direction, the cut off is raised while the nut tightens. This regulates how long the water pump will cycle prior to switching off. Make sure that the smaller nut and spring are not adjusted in such a way that the cut-off pressure is lower than the cut-on or else the water pump will go into a continuous, never ending cycle, which may eventually cause damage to the pump.
Replace the casing
After having adequately adjusted the pressure control switch and the pressure pump starts to cycle correctly, it is time to restore the casing on top of the water pump pressure control switch. Using your pliers, fasten the nut on the casing back in position. Upon making sure that the control switch is securely covered, switch on the power and make certain the pressure pump is working as well as cycling as it should be.