I just installed a March 809 hot pump on my system and was excited to use it for circulating the mash before starting to drain into the boil kettle. I ran the pump full open right off the bat and it worked great at clearing up the runnings, but the amont of wort being pumped back into the kettle quickly became less and less. Then when I ran from mash to boil, it ran super slow with or without the pump, it almost seems to me that the pump sucked the grain into my false bottom and cause it to clog, any body had anything like this happen to them while using a pump? This was my first stuck mash EVER! and I didn't like it much.