CleaverBrooks ClearFire CFH, Operation, Service And Parts Manual

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Chapter 3 — Flue and Combustion Air Venting
3-2 Part No. 750-295
3.1-VENTING CONNECTIONS — GENERAL
Proper installation of flue gas exhaust venting is critical for the efficient and safe operation of the ClearFire
®
boiler.
Definition of Appliance Categories
Boilers are divided into four categories based on the pressure and temperature produced in the exhaust
stack and the likelihood of condensate production in the vent.
• Category I - A boiler which operates with a non-positive vent static pressure and with a vent gas
temperature that avoids excessive condensate production in the vent.
• Category II - A boiler which operates with a non-positive vent static pressure and with a vent gas
temperature that may cause excessive condensate production in the vent.
• 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.
The ClearFire
®
-H can be considered a Category II, III or IV boiler as deemed appropriate for the application.
For additional information on boiler categorization, see 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.
During winter months check the flue termination and make sure no blockage occurs from build up of ice or
snow. Condensate can freeze on a flue termination. Frozen condensation at the flue termination can result
in a blocked flue condition.
3.2-FLUE VENTING
The flue should be supported to maintain proper clearances from combustible materials.
Use insulated vent pipe spacers where the venting passes through combustible roofs and walls.
Cleaver-Brooks recommends the use of flue venting systems that are certified to UL 103 or ULC C-959.
Flue systems constructed of stainless steel are recommended.
Please note: Type B vent is NOT
appropriate for Category II, III, or IV boiler systems.
! Warning
Contact the manufacturer of the vent material if there is any
question about the boiler categorization and suitability of a
vent material for application on a Category III vent system.
Using improper venting materials can result in personal
injury, death or property damage.
Notice
Notice