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.