So we got this house with a pool and waterfall years ago. All worked fine. Back then we used to hire out closing/opening as we were pool clueless. Seems one season the waterfall stopped working. Since I have tried to troubleshoot with no luck. The pump doesn't prime or engage ( sorry not sure the proper word ) . I can sit there with a hose pouring water in and it never tops off. I have taken the pump partially apart, the impeller looks new. I have replaced the orings. Not sure what to do next. The waterfall is on it's own "plumbing circuit" distinct from the pools system ( even on it's own breaker ) . Here some shots , hope someone has some ideas/experience with this soft of thing and can lend some advice. Thx in advance !!!!!