I have a drilled well (that is, not sand point) with a jet pump and pressure tank. Today the pump started turning on even though no water was being used. Watching the pump pressure guage, once the pump shuts off, the pressure ever so slowly drops until it engages.
I have branch-isolating ball-valves in my system so I was able to reduce the pipe system to just the main line and the pressure tank. I inspected the main line for leaks, and there are none.
I have an isolatin valve on the pressure tank too. When I close it, the pressure guage on the pump drops more quickly. When I oprn the valve again, I hear water rush out of the tank and the pressure jumps back up, then continues to drop slowly.
In other words, it sounds to me like my foot valve is allowing back-flow. Either that or I have a leak in the pipes on the well-side of the pump.
But I have a couple of questions:
1) I would have thought that the pump itself prevented backflow from the plumbing system. That the foot valve served only to stop the water in the inlet pipes from back-flowing. If ths is true, then it may just be my pump. Can someone tell me if jet pumps are supposed to allow back-flow?
2) If it is my foot valve, just how hard is it to change one? I mean "hard" in the sense of, are there any special tricks or tools required. It seems to me that it should just be a matter of pulling the well cap, pulling up the hoses, clamping on a new foot valve, lowering it back down, and priming the lines ready to go - - but I may just be ignorant of some subtlety that makes it impossible for me.
3) The other variable for consideration is cost - if the labour to do this is usually just ~$100, I'll just fcall someone. If a foot valve is $50 but the labour is $1,000, I'll learn how to do it and do it.