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:
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 |