MACH
®
Gas Fired Boiler
13
•
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
The MACH
®
C750, C900 and C1050 boilers are dual-certified as both Category II and Category IV appliances, which
vent with a temperature that is likely to cause condensation in the vent. Refer to Section 3.5.3.2 for requirements of
Category II installations and Section 3.5.3.3 for requirements of Category IV installations. Any venting system used
with the MACH
®
boiler must comply with the applicable venting system category as specified 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.
The venting materials listed below are intended for the venting of gas burning appliances 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.
This boiler is not certified for use with PVC venting. Use of PVC vent may
result in vent failure and possible serious injury or death.
According to ANSI Z21.13,/CSA 4.9, Gas-Fired Low Pressure Steam and Hot Water Boilers, Table XVII
“Maximum Allowable Temperatures of Typical Non-Metallic Vent Material” the maximum allowable
temperature for PVC is 158°F (70°) and for CPVC is 210°F (100°C).
Table of Acceptable Materials for Venting Systems
Manufactured Venting
US and Canada
Factory Fabricated Metallic Vent Systems listed and labeled to UL1738 (Titled:
Venting Systems for Gas-
Burning Appliances, Categories II, III, and IV)
Non-metallic Venting
Within the US
CPVC pipe conforming to ASTM F441, fittings conforming to ASTM F439 (Sch 80). Joints are to be sealed
with solvent conforming to ASTM F493.
Within Canada
CPVC Pipe, Fittings and Sealant listed and labeled to ULC S-636
Standard for Type BH Venting Systems
Table 1.3.2 Applicable Vent Materials By Boiler Model
As per ANSI Z21.13b-2012 * CSA 4.9b-2012:
* The use of cellular core PVC, CPVC and Radel as venting materials is prohibited.
* The use of external insulation on plastic vent pipe is prohibited.