I have a QUaker wall furnace that won't lite. I did in fact extend the vent pipe away from the exteroir by 2 feet as it was almost burning the exterior wood. Then I noticed on a face plate to use only special No9 vent. Any idea what that is? Did I change something with air flow by extending the vent?
Thanks Chris

Does it have a standing pilot light? Or electronic igniter?

does it have a standing pilot light? or electronic igniter?
HI, And thanks for responding. Since then I have contacted a local HVAC guy and since I extended the vent from 6" to 2' I have discovered my problem. The samll 6" vent that was on the unit takes in and vents it out. Since I changed all that I can only get exhause out. There is no "air in" to make it all work. I'll need to change the venting again to the original.
Thanks
Chris