Update- The vinegar bath worked like a charm, I swapped it with my other WP2 so I can go ahead and give that one a bath too. I went straight 100% vinegar for 4 days and this AM scrubbed it with a bluepad and water. I also tried to turn the impeller by hand to see if it free spins. I then plugged it in and it works great- so far not error message. If you own these type power heads I highly suggest you do the vinegar bath when you see it with lots of coralline growth, it might have other stuff growing inside that might junk it up...