When we had our house built over ten years ago, I had a wall switch
installed for the 50 gal water heater. The reason being that at
that time, we were pulling a 5'th wheel travel trailer around the
country and were often gone for a couple months at a time. Turning
off the water heater made sense; we also turned off the inline water
supple to the heater.

My question, and I don't know why I didn't think of it years ago,
is:
Would it be economical to turn off the heater at night and back on
in the mornings. One thought says, "yes", but the other is that it
would have to reheat the water equal to the overnight lost temp, and
wouldn't save anything.

Your thoughts please.
Bob-tx
PS: OT, but along the same lines. We also had the garage door
opener put on a wall switch so it could be turned off during periods
of absence. These switches are mounted about six feet high so they
are not confused for light switches.