I'm trying to diagnose a strange noise coming from my Pentair Whisperflo pool pump. It's not that old of a pump- I installed it in October 2018. It's working fine for the moment, but I've recently noticed a strange metallic rattle sound coming from it. The noise is especially noticable as it comes to a stop after running in low mode. To my ear it sounds like it's coming from a spinning internal piece, making me suspect the Impeller. When I turn the pump off, reach in, and turn the impeller it spins freely, with only an extremely faint squeak every rotation. As with all sounds, describing them is much more difficult than to just let you all hear it for yourselves. So, I made a short video that I posted on YouTube where I turn the pump on and off a few times, and you can hear the "problem sound" quite clearly. I'd appreciate any of you taking a quick look, here's the link:
I'm trying to get ahead of this problem- I'd much prefer to repair this pump now, before it fails and my pool goes down in the middle of prime swimming season! Any help or tips you guys would have would be greatly appreciated!