Well Pump Basics

Subscribe to get access to our how-to videos.

Well pumps are very basic but it helps to know what your looking at.  The well is the hole drilled in the ground.  Near the bottom is the pump that is hanging on a pipe.  When you use water, the pump turns on and supplies your home with the water it needs.  Any water not used is stored in the pressure tank which acts as a holding vessel and as a water hammer shock absorber.  When the system reaches a pre-set pressure (usually around 50-60 psi), the pressure switch turns the pump off.  When you use water out of the pressure tank, the pressure will slowly drop until the switch tells the system to turn back on (usually around 30-40 psi).  Understanding this basic concept will help you troubleshoot your system and make some easy repairs without the help of a professional.

This is your pressure switch with the lid removed.  All pressure switch look about the same and preform the same function of turning the well pump on and off.  They do this as water pressure from the small pipe pushes up on a tension spring plate on the bottom of the switch.  Adjusting the spring tension nut will adjust the pressure at which the switch opens and closes.  Tightening the nut increases the pressure and loosing reduces the pressure.  The main spring adjusts the pressure on both the low and high side at the same time while the smaller spring is used to adjust the cut-out or high pressure only.  If insects or any foreign object manages to get in between the points as they close, they will not allow power to goto the control box and the pump will not start.  Start by turning off the power to the well pump and verify that it is off.  then, using a fingernail file or flat head screwdriver, gently clean the points and restore power to the system.  Please note that it helps to verify that you have 230 volts at L1 and L2 inside the control box.  If you don't, try cleaning the points again.

This is the underside of your control box where the reset buttons are located.  Well pumps with a horsepower rating of 1.5 and above will have these buttons on them.  Well pumps with 1 hp or below do not contain reset buttons on their standard control boxes.  Occasionally, power outages and lightning strikes will cause these reset buttons to trip which will cause the well pump to shut down.  Push each button very firmly and if it is tripped, you will hear an audible click followed by the pump starting.  If the pump runs for a short period of time and you hear a "ping," followed by another shutdown.  Do not attempt to reset the pump again, this indicates a more serious problems either with the control box or the pump itself and should be looked at by your local pump professional.