furnace and dometic heat pump interaction

[MMulcahy]

When I turn on my furnace, my dometic a/c unit comes on (didn't get a manual for this component). I'm not set on heat pump. why does this happen? also, the furnance will stop blowing air pretty quickly but the dometic will continue to blow and the air is not particularly warm.

lastly, there is a vent opening on the dometic unit that seems to direct air to the ducts, or directly out of the dometic unit. anyone know why the difference? should it be in a certain position for furnace operation?

thanks all.

[n-e-d]

Select Fan on your thermostat and select Auto and only furnace fan will run. If your fan is on HI or Lo A/C fan will run with furnace. The vent on the Domectic will dump all its air at the unit unless its closed-then it will feed the ducts