Typical vent or stack temperature of a Category III furnace is:

The typical vent or stack temperature of a Category III furnace falls within the range of 280°F to 300°F. This range is characteristic of Category III appliances, which are designed for use with non-condensing venting systems. These systems can handle the higher temperatures produced by the furnace without the risk of condensate forming in the vent pipes, which is a concern in Category IV systems that operate at lower temperatures and are designed for condensing applications.

Understanding the temperature ranges is crucial for maintaining efficiency and safety. Category III appliances ensure that exhaust gases are vented properly and do not lead to issues like corrosion in the flue, as the higher temperatures help in keeping the exhaust gases above condensation points. This prevents potential damage and enhances the longevity of the venting system.

Maintaining vent temperatures within this range is important for optimal performance and compliance with industry standards.