The house was raised on stilts and pvc to septic was cut. Plumbers came in and reconnected pipes, but they system sat with an open pipe for a while. Now that every thing is reconnected, when the pump is plugged in, it trips the GFCI right away. I dug down to where the cords (2 of them) go into the system. There are no breaks in the line that I've found. When I run an extension cord to a non GFCI outlet it runs. (But I'm not sure if it is moving water.) Please help And I changed the GFCI.