Early morning panic. Started to heat the mash-in water and discovered my wort pump was locked up. Disassembled it right there. Cleaned, added missing SS washer (do all March 809's have this missing washer?), reassembled and back on track. Just an hour and a half late.
This will be a long day.
BTW - thanks to
Awesome Brewers for the tip on March 809 repair. That's what I love about good equipment. It's usually pretty straightforward to repair. I did luck out finding the SS washer I needed in "inventory".
One other benefit: it's clear that even though I rinse thoroughly and copiously with hot water after brewday, that is not enough. There was a film of dried wort inside this pump. This may have been been the cause of the "stuckness".
New practice adopted after every brewday: circulate hot PBW through pumps for 10-15 minutes.