i have fedders home heater(seems very old) it is like a rectangluar box and with little manual access. i can see the flame and i hear the sound of air blowing but still their is no potential hea t i witness :confused: and i tried turning it on and off (the thermostrat) but still no change in the situation :mad: please help...!!!

when last time u changed the filter,,,,,,has to have air coming in before it can blow out