Need HVAC help

[indy440]

@crAppAchic0

If that has a separate combustion air intake- check to see if/where it is plugged. Some older ones pull from around the roof jack, others pull from a separate intake hose isolated from the actual furnace compartment. If the inspection window is open and it pulls intake air from there, the flame would be fine until you close it and the flame would starve out without intake air.

Could also be a near-dead/clogged burner motor, also, I guess?

(Not a HVAC pro by any means, but have spent some time with it.)

Best I can tell it pulls air right on the front of the furnace, i’ll check closely for anything that might be obstructing flow. The way the flame burns (like a torch) it doesnt seem like it would be starving for air from there though.