Which is not considered a vent connector problem on wood furnaces?

The reason that having less than 5 feet from the furnace to the chimney is not considered a vent connector problem is tied to the design and function of venting systems. In vent connector systems, the primary concern revolves around how the connectors facilitate the proper flow of combustion gases from the appliance to the chimney.

While there are guidelines about the distance between the vent connector and the chimney, they generally focus more on ensuring that the venting is appropriately designed to minimize backdrafts and ensure proper exhaust. Having less than 5 feet does not inherently indicate a problem unless other factors, like inadequate slope or location of bends, are compromised.

In contrast, other options directly relate to safety and operational effectiveness. For instance, if combustible material clearance is less than 18 inches, it poses a fire hazard. A vent connector made of galvanized steel might not be suitable depending on the temperature of the exhaust gases and the potential for corrosion. Finally, having four 90° elbows creates excessive resistance to airflow, which can lead to poor venting efficiencies and a buildup of dangerous gases. Thus, option A stands apart from these clear-cut issues impacting safety and performance, identifying it as not being a vent connector problem in the context of wood furnaces.