Effective immediately, venting systems for flue gas from gas-fired appliances must comply with SPS 323.14 and the 2015 NFPA 54 Chapter 12, Section 12.5 requirements for types of venting systems. The change comes with the adoption of the 2021 International Codes.
All commercial installations using Gas-Burning Appliances in Categories II, III, and IV now require plastic pipe venting systems to be listed and labeled according to ANSI / UL 1738 standards.
The ASTM D1785 standard does not address the use of PVC piping products for venting combustion gases from water heaters, furnaces, or boilers. In contrast, UL 1738 includes specific testing and marking requirements for flue gas venting products such as PVC.
###
