Quote Originally Posted by stick47 View Post
Don't forget about ONG charging a minimum $13/mo service fee. (twice that if a heavy user) At our last house with a NG 40 gl WH my wife just checked and our bill in the summer was always close to $38/mo. So the math does work for a Hybrid WH IMO.
ONG does lay the base meter charges on thick, but the gas itself is quite cheap. Once you pay the hefty monthly service charge, run as much on the cheap NG as possible. This is why the HP water heater doesn't make economic sense for those on ONG. Neither do dual fuel heating systems for that matter.