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All installations and services must be performed by qualified service personnel.
12
J. Venting
1. Vertical Venting
• The vent installation of this Category I furnace must be in
accordance with National Fuel Gas Code, NFPA 54/ANSI Z223.1-2002
or latest edition, and/or local building codes and these instructions.
• A furnace or any other gas utilization equipment must not be
connected to a chimney flue serving a separate appliance designed
to burn solid fuel.
• When venting two or more appliances into a common vent, the
smallest appliance must be vented into the top opening.
• The maximum gross stack temperature must not exceed 480°F
(249°C) under any circumstances
NOTICE: This section does not apply to units, which are sidewall vented. For
sidewall venting, see Section II, K, of this manual.
The following requirements must be followed when connecting this furnace to a
vent system.
The MHA1/MDA1 (induced draft gas highboy and counterflow/horizontal) series
furnace must be vented in accordance with these instructions into a factory built
chimney or vent complying with a recognized standard. Type B1 or double wall
vent as well as masonry chimneys lined with a lining material acceptable to the
authority having jurisdiction are acceptable as described in the venting tables
included in the appendix of the National Fuel Gas Code, NFPA 54/ANSI Z223.1-
2002, or latest edition.
A good vent is one that is sealed and has the capability of producing a -0.04 in.
W.G. draft with the capacity of handling the amount of flue gas that is introduced
to it.
The vent must be vertical or nearly vertical in design, unless equipped with a UL
listed mechanical venter.
This furnace must not be connected into any portion of a mechanical draft
system operating under a positive pressure.
This furnace shall not be vented into an unlined masonry or concrete chimney.
PVC piping is not an acceptable substitute for a chimney or a flue connector. A
chimney with an internal construction of stainless steel or some other material
that will withstand a gross flue gas temperature of 480ºF is required.