I have an Ultra Wash Dishwasher, Model 665.13843. I find the manual confusing as to how the Heated Dry works. Does Heated Dry automatically come on in certain cycles, or does it comeon only if I have pressed the Heated Dry button at the beginning ofthe cycle and the Heated Dry light is lit?

Yes, as far as I know, at least on any dishwasher I have had to the present one, the heated dry cycle comes on automatically.