http://www.pushhogg.com/energy-saving-hot-water-heaters/
Can I turn down one of two water heaters connected in parallel?
My house has two water heater tanks, both connected in parallel and to the same hot water supply. To save energy, I’d like to turn one down to “Vacation” mode. To avoid mixing the cold water from this one with the hot water from the other, I want to turn the hot water outlet off on the one in Vacation mode.
Is there any downside to this? Can I safely close the hot water outlet on a water heater that is still “on”?
These are natural gas powered water heaters.
The heaters are not in serial, they are in parallel. Which means that water does not flow from one to the other, the cold water intake splits and gives off a branch to each, then the hot water outlets join together and go into the house supply. I think the solutions below are talking about tanks in serial.
One should be set at a lower temp anyway so you can get a better flow, it should be like a preheater to the main tank. You can bypass it altogether if you don’t need the additional hot water, just turn the gas off to the tank you don’t want and turn your water valves to bypass or it will just circulate through the off tank. It would then feed cold through the cold side of the tank you are still using the same as if you had it hooked up to the cold water from the house.
Conserving energy via hot water heater?