Recently, my central air ran out of freon so this summer I couldn't cool my house.Now my
Unit will not blow out any heat. I tried to turn the heater on but it smelled like it was trying
To catch on fire. All I want to know is do I need to apply freon to get my unit to produce
Heat?

No,, unless you have a heat pump,, it needs freon to make heat,, but most heat pumps have a furnace to back up or work when the heatpump can`t do the job,, does your thermostat have an emergancy heat mode?