Air Shutter Setting - Heatilator NNXT4236IF Installation Manual

E. Air Shutter Setting
Air shutter settings should be adjusted by a qualifi ed ser-
vice technician at the time of installation. The air shutter is
set at the factory for minimum vertical vent run. Adjust air
shutter for longer vertical runs. See Figure 9.1.
• Turn the thumbscrew to open and close.
NOTICE: If sooting occurs, provide more air by opening
the air shutter.
Close Open
Figure 9.1 Air Shutter
40 Heatilator • NNXT4236IF, NNXT4236ILF, NNXT3633IF, NNXT3633ILF Installation Manual • 4055-980 Rev. D • 9/15