This type of installation can cause non warrantable problems with components and poor operation of the unit due to the recirculation of flue products. Multiple direct vent caps, when installed in the same horizontal plane, should have three (3) foot clearance from the side of one vent cap to the side of the adjacent vent cap(s).
Combustion air supplied from outdoors must be free of particulate and chemical contaminants. To avoid a blocked flue condition, keep the vent cap clear of snow, ice, leaves, debris, etc.
WARNING: For common vent installations call factory.
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 direct vent cap must be fur- nished by the boiler manufacturer in accordance with its listing.
Fig. 24: Vertical Direct Venting/Combustion Air
(Category I)
*Vent lengths are based on a lateral length of 2 feet. Refer to the latest edition of National Fuel Gas Code for further details (ANSI Z223.1) or in Canada, the latest edition of CSA B149 Installation Code.
Table N: Vertical Direct Venting without
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