That's helpful insight!
It must be doing that, because all agree that the water appears hotter (at least at first) with the recirculation pump turned off.
This morning, I tested the shower, and it took 8 seconds (one onethousand, two one thousand, etc.) for it to get hot enough to hurt.
So, the recirc pump, in essence only subtracted 8 seconds from the time- to-hot-water point, but, it also cooled that hot water, and made a whole lott'a vibratory noise (due to the lousy mounting).
I consider it a win:win with the darn thing unplugged.
I'm just not sure whether to leave the three valves in the open or closed positions.