Won't Miss #206 - troublesome water heating

A selection of shower water heaters. Note the plethora of knobs and dials.
One thing which I find a cumbersome and irritating chore day-in and day-out  is having to fuss with the mechanism in my shower for getting the water to come out hot. Even though I have a new water heater and not some antique system, I still have to go through a process every night where I turn a crank about 10 times while