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• Vertical Direct Venting System With Add-on Condensing Heat Exchanger (Category IV) Installation
These installations utilize the boiler mounted blower to draw combustion air from outdoors and vent combustion prod-
ucts to the outdoors.
UL 17-38 Certified Venting Material (e.g. AL29-4C) MUST be used. The vent must be installed to prevent flue gas leakage.
Care must be taken during assembly to insure that all joints are sealed properly and are airtight.
For certain installations, i.e. pool, heat-pump, domestic hot water supply with pre-heat tank, PVC or CPVC may be used.
Contact manufacturer for details.
To prevent the condensation accumulation in the vent, it is required to install the horizontal portion of vent with a slight
upward slope of not more than 1/4" per foot of horizontal run and an approved condensate trap must be installed per
applicable codes.
WARNING: Pressurized common vent installations should be engineered.
WARNING: No substitutions of flue pipe or vent cap material are allowed. Such substitutions would jeopardize the
safety and health of inhabitants.
The Stainless Steel non-restricted direct vent cap must be furnished by the boiler manufacturer in accordance
with AGA/CGA requirements.