2017 Cougar 29res heat issue

[Brenden820]

I recently purchased this pre-owned unit, and turned the heat on for the first time today. I set the thermostat to 75 degrees, and I can hear the furnace fire so that’s not a problem. But the blower in the a/c unit comes on blowing air thru the roof vents. The registers in the floor barely have heat blowing out of them. Any ideas? I’m confused....