I have a Whisperflo 2HP pump for my Sheer Descent waterfall. It has been operating flawlessly for two years. It recently started losing its prime and the pump pot would intermittently fill and partially empty with water, causing an inconsistent flow to the waterfall. I’ve inspected the lid, lid gasket and piping for cracks and all seems ok. I’ve attempted to feel for debris in the impeller but can’t reach that far into the pump.
After re-filling the pump w/ water and re-starting, it appears to operate fine for a few minutes and then the inconsistent emptying and filling of the pump pot starts again. The pump never stops pumping, but continues to pump intermittently.