I have a pump I end up using just for general yard watering. It ended up running overnight. Usually is shuts off on its own and I switch the power off. I ended up not switching the power off and heard it running the next morning. Anyways... Symptoms are: - It sounds like it is pumping - No water comes out the hoses - I prime the pipe above and the water doesn't go down from running the pump - I remove the screw on top of the pump and water flows up and out (whether the pump is on or off) so it looks like water is in the pump. The pump is only a year old. Not sure what else to do.