You'll want to recirc back to the kettle before flameout to sanitize the CFC but then what Lil Sparky said... If the CFC output isn't quite as low as you hoped, you can recirc back until the whole wort is down near 140F, then redirect to the fermenter. This also serves to bring you down under DMS production zone and as mentioned above, lock in your aroma hops. I only do this if I can't run the pump at full bore. If I can, the 10 gallons drain in less than 5 minutes and I don't worry about aroma or DMS. Beware though, recirculating to the kettle puts cold break in and you might want to catch it in a hop bag or something so it doesn't eventually clog your pickup tube.