Heatilator Vented Gas Fireplace NBV3630 Owner's Manual page 29

P. Air Shutter Setting
Air shutter setting should be adjusted by a qualifi ed installer
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 12.14.
• Turn the thumbscrew to open and close.
Close
Figure 12.14 Adjusting Air Shutter
Open
Heatilator • Novus NBV • 4055-188 Rev C • 04/08 29