The Department has issued a new Buildings Bulletin that specifically clarifies the applicability of section FGC 502.1 of the 2014 NYC Fuel Gas Code (FGC) which mandates the use of listed and labeled plastic pipe as vent pipe serving Category IV appliances. For more details on the requirements, please read Buildings Bulletin 2021-001. You can also read our Bulletin Highlight. For questions on the requirements, you may contact us at constructioncodes@buildings.nyc.gov.

What are Category IV appliances?
Category IV appliances are condensing, high efficiency appliances, such as water heaters and furnaces, for example, whose vent systems are usually constructed of polypropylene, CPVC, or stainless steel piping.

What type of pipe materials are no longer allowed?
Due to a code modification from the 2008 NYC FGC to the 2014 NYC FGC, the following are no longer allowed for venting Category IV appliances:

• All PVC pipe (both listed and unlisted)

• Unlisted CPVC pipe

Why are PVCs and unlisted CPVC pipes not allowed in Category IV appliances?
PVC and unlisted CPVC pipes have been shown to fail through discoloration and melting when subjected to high temperatures associated with Category IV appliances.

What is allowed for venting Category IV appliances?
Listed CPVC pipe

Need more information?
For additional information, please consult the Department of Buildings resources below.

Buildings Bulletin 2021-001

Bulletin Highlights