I just replaced my old Zoeller M53 pump with a new one, to "buy me some time" while I replaced the float switch on my old one. I re-did the vertical discharge pipe, which is only 26 inches high, and includes a Flo Tec check valve, and following Zoeller's recommendation, drilled a 3/16" hole on the 1 1/2" PVC pipe about even with the top of the pump. Now the pump works just fine, but is a little noisier than the old pump. As an experiment, once I replaced the float switch on the old Zoeller M53, I pulled out the new pump , and hooked up the new plumbing, to the old pump, and dropped it into the pit, and it is STILL noisier. So, that ruled out the possibility that there was anything wrong with the NEW pump, like bearings? Both pumps seem to give off a louder low pitched vibration than before. Before, I could hardly hear the Zoeller pump going on, except for the metal handle vibrating slightly on the pump. I even cleaned any rocks or pebbles off the bottom of the concrete pit, and made sure the pump was sitting squarely and solidly on the concrete bottom.
About the ONLY difference I can see is that the old setup had the ZOELLER 30151 check valve, installed at the bottom of the pump (with NO "weep hole" drilled into the pipe). Now I learned that the Zoeller 30151 is designated "FULL FLOW". Has anyone else experienced that the Zoeller check valve was QUIETER than the "Big Box" stores variety check valves? Of course, I guess I could ELIMINATE the Flotec check valve temporarily to see if it quiets down? But before I start undoing and redoing, maybe someone has experienced this phenomenon.
Does anyone know if the Flotec is "Full FLOW"???? And what the heck does "Full Flow" MEAN?
Oh, and by the way- I can't put the OLD plumbing back on that a plumber installed years ago because I had to cut it off and just about destroy everything to get it off-hence- my new re design. Long story.