I have a Pentair WhisperFlo (Model No. WFE-8) as a pump for a water feature (slide/waterfall). A couple weeks ago when I turned it on, all I heard was buzzing. I quickly turned it off, then back on and it worked perfectly. This past weekend, I turned it on. Again, the buzzing was heard, but before I could turn it off it went dead and now remains that way. I'm fairly handy and I've repaired my pool heater via TFP myself so before I go about cutting pipes and dragging the unit to the pool shop.....does anyone have any ideas? Trouble shooting checklist, etc?