# 45465K005
Page 15
Bottom Filter Location
Upflow Models
Figure 20
Filter
Base
Side
Bottom Return
G2D80CT series furnaces are designed with a special
knockout base pan for bottom return applications. The
removable pan is perforated and held in place by small
metal tabs that must be detached before removing the
knockout base. No special tools are needed.
Counterflow Applications
Filters are not supplied with G1D80BR and G2D80CR
series furnaces; however, filters must be used. It is the
installer’s responsibility to install properly sized filters in
accordance with Table 2.
If filters are needed at furnace only, use the following kits:
•
AFILT529 – bottom return or horizontal applications
•
AFILT525 – counterflow applications
Gas Supply and Piping
Refer to the furnace rating plate to make sure the furnace
is equipped to burn the gas supplied (natural or propane).
To remove the NO
x
inserts, first take out the burners. After
removing the burners, remove the screw holding each
insert and pull the insert from the combustion chamber
(see Figure 21).
The screws must be re-installed in the
vest panel after the inserts are removed.
NO
x
Insert
Location
Figure 21
When converting a low NO
x
furnace (desig-
nated by an “L” in the model number, such as
G1D80BT100D20CL-1A) to propane, the
NO
x
inserts must be removed. Failure to
remove the inserts can create a situation
where carbon monoxide is produced which
may lead to asphyxiation.
WARNING
Any conversion of a natural gas unit to pro-
pane gas must be done by qualified personnel
using a conversion kit available from the
manufacturer, following the instructions in the
conversion kit. If done improperly, overfiring of
the burners and improper burner operation
can result. This can create carbon monoxide
which could cause asphyxiation.
WARNING
Table 2
Minimum Filter Requirements
1.
The Airflow Descriptor is the two digits following
the “D” in the model number.
2.
Areas and dimensions shown for cleanable
filters are based on filters rated at 600 feet per
minute face velocity.
3.
Typical filter sizes are shown; however, any
combination of filters whose area equals or
exceeds the minimum area shown is satisfactory.
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