SECTION J: VENTING CONNECTIONS
GENERAL
CAUTION: Proper installation of flue exhaust venting is critical for the safe and efficient operation of the boiler. For vent systems not shown in this section please contact your local authorized representative.
Definition of Appliance Categories
Boilers are divided into four categories based on the pressure produced in the exhaust and the likelihood of condensate production in the vent.
Category I. A boiler which operates with a
Category II. A boiler which operates with a
Category III. A boiler which operates with a positive vent pressure and with a vent gas temperature that avoids excessive condensate production in the vent.
Category IV. A boiler which operates with a positive vent pressure and with a vent gas temperature that may cause excessive condensate production in the vent.
See Table
Note: For additional information on appliance categorization, see appropriate ANSI Z21 Standard and the latest edition Standard of National Fuel Gas Code or in Canada, the latest edition of CGA Standard B149 Installation Code for Gas Burning Appliances and Equipment, or applicable provisions of local building codes.
Determination of Appliance Category for Venting Purposes and Venting Arrangements
WARNING:
Contact the manufacturer of the vent material if there is any question about the appliance categori- zation and suitability of a vent material for application on a Category III or IV vent system. Using improper venting materials can result in personal injury, death or property damage.
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