Harsco Industrial 1004905923 Installation & Owner's Manual page 13

boiler is to be installed in a conventional or Direct Vent configuration. In the US, provisions for combustion and
ventilation air must be in accordance with NFPA 54/ANSI Z223.1, National Fuel Gas Code, latest edition, or
applicable provisions of the local building codes. In Canada, combustion and ventilation air openings shall
comply with CAN/CSA B-149.1 Natural Gas and Propane Installation Code.
manufacturer's instructions.
Failure to use a proper vent system (types and materials), as described in this manual will void the boiler war-
ranty and may result in rapid deterioration of the venting system, creating a health or life safety hazard.
Faulty vent installation can allow toxic fumes to be released into living areas. This may cause property dam-
age, serious bodily injury or death.
3.5.1.1 Gas Vent Categories
Several codes and standards have categorized appliances in accordance with the flue gas temperature and pres-
sure produced by the appliance. Categories are defined as follows:

Category I An appliance that operates with a non-positive vent static pressure and with a vent tempera-
ture that avoids excessive condensate production in the vent.

Category II An appliance that operates with a non-positive vent static pressure and with a vent tempera-
ture that may cause excessive condensate production in the vent.

Category III An appliance that operates with a positive vent static pressure and with a vent temperature
that avoids excessive condensate production in the vent.

Category IV An appliance that operates with a positive vent static pressure and with a vent temperature
that may cause excessive condensate production in the vent.

Direct Vent An appliance that is constructed and installed so that all air for combustion is derived directly
from outdoors and all flue gases are discharged to the outdoors.
3.5.1.2 Venting Materials for Flue/Exhaust Systems
®
MODU-FIRE Forced Draft boilers are Category IV appliances, which vent with a positive exhaust pressure and
with a temperature that is likely to cause condensation in the vent. Therefore, any venting system used with the
®
MODU-FIRE Forced Draft boiler must comply with the requirements for Category IV venting systems as speci-
fied in the latest edition of NFPA 54/ANSI Z223.1 in the US or the latest edition of CAN/CSA B-149.1 in Canada.
pliances only. Do not use these venting materials for venting liquid or solid fuel (such as oil, kerosene, wood or
coal) appliances.
Maintain clearances to combustibles as listed in the vent manufacturer's installation instructions or as set forth
in the codes and standards listed in this section.
Do not use these vent pipes for incinerators of any sort.
3.5.2 Combustion Air
Combustion air must be free from dust, lint, etc. The presence of such materials in the air supplied to the burner
could cause nuisance "Low Air" shutdowns or premature burner failure. The boiler should not be operated during
construction while the possibility of drywall dust, demolition dust, etc. exists.
Before connecting a boiler to a venting system, it must be determined whether the
For correct installation of vent system, read all of these instructions and refer to vent
The venting materials listed below are intended for the venting of gas burning ap-
®
MODU-FIRE Forced Draft Gas-Fired Boiler 2500-3000
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