2009 Chrysler 300 heat only blows up

The heat blows from the defroster up top instead of floor, even when the floor heat is selected. what could be the problem?

Broken actuator that moves the air control doors.

Defrost is the default mode position for a faulty actuator. There are simple ways to calibrate the blend doors. You can also check for trouble codes using buttons on the climate control module. Do you have automatic or manual control? And does it have dual side controls. If you do these tests and calibration it will probably end up as a bad actuator anyways. Are you going to do the repairs yourself?