The basement heat is all tied together in one system so there's no separate switch I know of. Wondering if your hose has come loose. You should be able to track the hose back to the heater fan housing (may be located on the ceiling of your main full pass-through storage area. Once you find it turn the heat on and get those fans going and see if you feel air blowing through an outlet flange that may be a hose connection. Of course - if the hose is in two parts the connection further downstream could have come loose.
If needed, on the passenger side of the coach in the bay that holds your water pump and one end of the water tank, you can remove the decorative wall board and literally climb over the water tank to see the back of the AH and add'l water / electric and other lines.
2015 Itasca Ellipse QD | 2014 Jeep Grand Cherokee