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5 - Guide filter and filter door into the filter rack which is
installed on the side of the furnace. Push door into fil
ter rack until secure.
6 - To remove filter, pull filter door pins until door is re
leased from filter rack.
FIGURE 10
FILTER DOOR ASSEMBLY
FILTER DOOR
PINS
FILTER
DOOR
FILTER
FILTER DOOR
PIN
TAB
TAB
Duct System
Size and install supply and return air duct system using
industryapproved standards that result in a quiet and
low-static system with a uniform air distribution. Refer
to ACCA (Air Conditioning Contractors of America)
Manual N.
Supply Air Plenum
Furnaces installed without a cooling coil require the
installation of a removable access panel in the supply air
duct. The access panel should be large enough to permit
inspection (either by smoke or reflected light) of the heat
exchanger for leaks after installation. The furnace ac
cess panel must always be in place when the furnace is
operating and it must not allow leaks into the supply air
duct system.
Return Air Plenum
NOTE - For bottom return air, return air duct should be se
cured to the unit using rivets or Slocks. For side return air,
secure return air duct to filter rack using screws. When us
ing screws, take care to avoid interference with the filter
which may cause improper filtration.
Return air must not be drawn from a room where this
furnace, or any other gas appliance (ie., a water heat
er), is installed.
When return air is drawn from a room,
a negative pressure is created in the room. If a gas ap
pliance is operating in a room with negative pressure, the
flue products can be pulled back down the vent pipe and
into the room. This reverse flow of the flue gas may result
in incomplete combustion and the formation of carbon
monoxide gas. This toxic gas might then be distributed
throughout the house by the furnace duct system.
Venting
G23(X) series furnaces must be vented in compliance
with all local codes, the venting tables provided in this
manual, and these instructions.
The G23(X) series units are classified as fan assisted
Category I type furnaces when vertically vented accord
ing to the latest edition of ANSI Z21.47 Central Furnace
Standard in the USA. The definition of a fan assisted
Category I type furnace is an appliance equipped with an
integral mechanical means to either draw or force prod
ucts of combustion through the combustion chamber and/
or heat exchanger.
The vent sizing tables in this manual were extracted from
the National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and
are provided as a guide for proper vent installation. Prop
er application, termination, construction and location of
vents must conform to local codes having jurisdiction. In
the absence of local codes, the NFGC serves as the de
fining document.
Refer to the tables and the venting information contained
in these instructions to properly size and install the vent
ing system.
The G23(X) series units have the following flue collar
sizes: -50 unit, 3 inch diameter; -75 and -100 units, 4 inch
diameter; and -125 & -150 units, 5 inch diameter. Use this
information in conjunction with the provided venting
tables to properly size the vent or vent connector that at
taches to the furnace flue collar.
Venting Using a Masonry Chimney
The following additional requirements apply when a lined
masonry chimney is used to vent an G23X furnace.
A Category I appliance must never be connected to a
chimney that is servicing a solid-fuel appliance. If a fire
place chimney flue is used to vent this appliance, the fire
place opening must be permanently sealed.
A chimney with one or more sides exposed to the outside
of the structure is considered to be an exterior chimney. A
Type B or listed chimney lining system passing through an
unused masonry chimney flue is not considered to be ex
posed to the outdoors.
Masonry chimneys used to vent Category I central fur
naces must be either tilelined or lined with a listed metal
lining system or dedicated gas vent. Unlined masonry
chimneys are prohibited.
