Man, now I'm lost. I turn on/off a switch in the fuse box. Thought that is the electric. Not even sure about gas side. Three is nothing in my control panel for either.
Due to projected temps in 20s tonight, I drained water at low drains and removed the heating element. (First time for me). I plan on closing low drain points, putting new element in, then turning on water. After reading these comments, I will do this before plugging in to electric.
I will explore the 'using both' aspect.