Furnace/Heat Pump question

[brad1]

Ok boys and girls, get ready for some amusing newbie type questions regarding the interior heating system. When I set the Dometic controller to Furnace, the unit in the ceiling comes on and begins to blow cool air, and warm air begins to emerge from the floor-level vents. Eventually warm air flows from the ceiling unit too.

I know that the ceiling unit is the air conditioner, and I assume it is also the heat pump and perhaps the fan system for the furnace. The ceiling unit is noisy, kind of objectionably noisy.

The very brief Dometic manual doesn't tell me much. I wish it explained more about the relationship between the furnace and the ceiling unit (and it's functions). Perhaps someone would be kind enough to give a brief rundown of how the system works.

Here are the main questions I have:

Is the ceiling unit always on when the furnace runs?

Is there any way to turn the ceiling unit off when the furnace is running?

Thanks!

[dkrug]

We have a 30' International. On ours the heat pump and the furnace work independently of each other. The ceiling unit is the A/C or heat and the furnace is just heat.
I can agree 100% on the heat pump being way too loud.

[lsbrodsky]

You probably have the CCC2 thermostat. If, while selected to FURN, you have the fanspeed selected to anything other than auto, then the roof unit fan will run to circulate air. In Auto, the fan will stay off and only the furnace fan will run.
Larry

[brad1]

I know this is awfully late, but Larry, thanks for the reply. You saved my butt from freezing one surprise snowy morning after an overnight stop at Shasta City.

[brad1]

Wait, I meant Ibrosky

[lsbrodsky]

It is Larry