2022 Coleman lantern 264 rl. Brand new camper nice machine. when I run the HVAC, there's the single thermostat on the wall. I put it on furnace and told it to heat. the gas furnace is working great it. turns on and off as demand is met. However, The air conditioner on the roof runs all the time. not cooling, but circulating, I guess. It blows the whole time the furnace is on. Stops when I turn furnace off at thermostat. is this normal can I change it?