Elec. heat v. Gas heat

I can tell you how mine works. The gas vs. electric heat is controlled by the thermostat. When you turn on electric heat, the thermostat may or may not also turn on the gas furnace depending on the spread between the room temp and set temp, plus some other algorithmic behavior built into the thermostat. Heat pump vs. heat strip is controlled by a non-adjustable thermostat in the roof unit. Above the set temp the heat pump runs, below the set temp the heat strip runs. I personally don't like this automatic behavior based on what somebody else decided I want, and have added switches to the thermostat and roof unit so I can force it to do what I want it to do.