[RKDinOKC]

Couldn't sleep. So...

My gas bill for July was $33.57 for gas used.
According to typical usage furnace and water heater pilot lights used 1,108,000 BTU of gas.
That's $3.68 of gas leaving $29.89 or 8,994,558 BTU to heat water.

Water heater is 40 gallons and 40,000 BTU.
Worst case scenario if set water heater to VAC setting it will get down to 55°F.
To heat 40 gallons of water from 55°F to 130°F is 75°F x 40 gallons = 3000 gallon degrees.
It takes 11 BTU to heat 1 gallon of water with gas.
To heat 40 gallons from 55 to 130 uses 3000 x 11 or 33,000 BTU or $0.11.
And would take my 40,000 BTU heater 50 minutes.

Maintaining 130°F used 8,994,558 BTU / 33,000 BTU means could heat from 55°F to 130°F 272 times for the same amount of gas used in a month. That makes it look like turning on/off water heat will save some money. Seems to make quite the argument for tankless water heaters also.

If I cycled the water from 55°F to 130°F twice a day it would cost $0.22 or $6.60 a month.
Adding in the pilots my total bill would decrease from $33.57 to a little over $10.28 a month.

Welp, going to have to start turning the water heater on/off to the VAC mode manually allowing an hour for heating to use hot water and see what happens both comfort wise and on next months bill. Or maybe read my own meter and see how much it ticks off in a week.
It would be nice if I could tell how often it ran like the fan time counter on the A/C.