Here is our problem. We have a shallow well pump that fills our pressure tank. Last night I noticed when the pump shut off, I heard running water and then the pump kicked back on. After making sure there were no open faucets or visible burst pipes, I unplugged the pump til I could look at it in the light of day. This is what I found: The pump fills the tank, shuts off and the water in the tank flows back out. I personally think that the back flow valve has somehow malfunctioned, but I've gotten all sorts of advice (non-plumbers) Any ideas?