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31-5000737 Rev. 0
Multiple Venting
The NF80LS furnace can vent in multiple positions. See
Figure 11.
The make up box may be removed and the combustion air
inducer may be rotated clockwise or counterclockwise 90°
to allow for vertical or horizontal vent discharge in a vertical
or horizontal cabinet position. Remove the four mounting
screws, rotate the assembly (assembly consists of orifice
plate, proving switch, gasket and combustion air inducer),
then reinstall the mounting screws. See unit Installation
Instructions for more detail.
The combustion air pressure switch must be moved for
horizontal discharge air left position.
IMPORTANT
Figure 11.
vent pipe
vent pipe
flue
transition
vent pipe
FLOW
AIR
flue transition
vent pipe
pressure switch
vent pipe
In all positions route the wires away from moving parts and the heat of the inducer
motor to prevent damage to the wires.
The pressure switch must be installed above
the CAI to prevent moisture from collecting in the hoses or switch.
FLOW
AIR
Collector Box
Vent Pipe
Pressure
Switch
vent pipe
Collector Box
FLOW
AIR
Pressure
Switch