American Tankless Water Heaters Venting

Tankless Venting

The water heater must be vented in accordance with the section “Venting of Equipment" of the latest edition of the National Fuel Gas Code: ANSI Z223.1/NFPA 54 in the United States and/or Section 7 of the CAN/CSA B149.1 Natural Gas and Propane Installation Code in Canada, as well as applicable local building codes.

General rules for venting water heaters are:

  • • Place the water heater as close as possible to the vent terminator.
  • • The vent collar of the heater must be fastened directly to an unobstructed vent pipe.
  • • Do not weld the vent pipe to the water heater’s vent collar.
  • • Do not cut the vent collar of the unit.
  • • The vent must be easily removable from the top of the water heater for normal service and inspection of the unit.
  • • The water heater vent must not be connected to any other gas appliance or vent stack.
  • • Avoid using an oversized vent pipe or using extremely long runs of the pipe.
  • • For rooftop venting, a rain cap or other form of termination that prevents rain water from entering into the water heater must be installed.
  • • Do not common vent or connect any vent from other appliances to the water heater vent.


Venting Installation Diagrams & Examples for American Tankless Water Heaters