: I have a fairly new 3/4 HP jet pump on my well system. It was running non-stop. It seemed like a sticking pressure switch so I replaced it. The new switch came factoy set at 20psi on and 40psi off. It still ran continuously, so I adjusted the cut out only until it shut off ten full turns is what it took (I need to install a pressure gage). Now the pump comes on immediately when the system is opened and goes off immediately when the system is closed, and the water supply is insufficient (washing machine filling in the basement causes no water in the kitchen sink). I checked the air pressure in the holding tank it is 40psi. My father thinks I should call the well service and have them check the foot valve and screen. [font color="navy"]What do you think?
You need to adjust the air in the pressure tank before you do anything else. Drain the water down completely and then check the air in the tank. It should be 2 lbs less than the kick on pressure for your pump. With a 20-40 switch, it should be set at 18. You are now going to have to fiddle around with your switch to get it back where it should be. Try to maintain a 20# differential between the on and off. I think you will be happier with a 30-50 or a 40-60 switch. I find 20#s pretty low.