To clarify, the dishwasher in question is presently always set to use the
cycle that heats the water, because the water is never reliably hot. Even
if we run the water to get it hot, it doesn't stay hot very long, because
the pipe is not insulated, and goes under the slab foundation.

Ideally, we should set it up with some kind of switch to be able to switch
back and forth between hot and cold water, so we can experiment with
different cycles etc., to see which get the dishes cleanest, and which
result in higher energy bills. Also, this dishwasher can take hours. But
even if we put it on its shortest, non-heating cycle, it still seems to
take hours. Or at least a long time.