I have had this furnace for three years. In that time, I have already had to replace a major part, a motor forcing warm air through the output ducts. Yesterday, with a brand new thermostat and batteries, the heater was set for 72 and would engage. I could watch the autolite work and the burner fire off. However, as soon as the air started being pushed out, the fire blew out and the unit would continue to blow cold air. Has this happened to anyone else? If so, what did you do to remedie it? Is it a part or repair that a average joe is capable of or do I need to call a service tech?

I have an Evcon/Coleman Furnace Model DGAA056BDTB, it is in a modular home with a digital thermostat. I have had the unit three years but I think the heater is about 5 years since it was installed.