Owners manual shows ball in air check at the bottom during slow rinse cycle.

I watched the ENTIRE regeneration and the ball NEVER dropped to the bottom.

Question---is something wrong with the unit, or is the owners' manual wrong?

FYI-Everything seems in good working order. Brine tank has been cleaned (spotless), and discs/valves flushed manually. The brine valve(#1) released a LOT of gunk.