The vent restrictor is located on the underside of the fi rebox top. The unit leaves the fac-
tory with the vent restrictor open. The restrictor is built into the appliance for secondary air
fl ow adjustment. Adjustment enables tuning the airfl ow for optimum fl ame appearance and
performance for a wide variety of vent confi gurations.
Setting:
• determine the vent height.
• determine the vent horizontal length.
• from the chart determine the restrictor position.
Refer to the chart in Fig. #44 for the correct position of restrictor for the vent confi guration
of your installation. Restrictor positions are based upon lab tests. The ideal position may
vary slightly with installation.
Restrictor position is too closed if the fl ame has the following characteristics:
• Flame is excessively tall and lifting.
• Flame lacks movement.
• Flame
soots.
Restrictor position is too open if the fl ame has the following characteristics:
• Flame height is low.
• Flame has excessive movement.
To adjust the restrictor:
• Loosen the screw holding the restrictor.
• Move the restrictor to its intended opening.
• Re-tighten the screw.
WALL AND ROOF
TERMINATION
RESTRICTOR POSITION
Fig. #44
VENT RESTRICTOR
12'
10'
30'
40'
48'
6'
4'
2'
0'
8'
30'
18"
4'
20'
22'
18'
20'
FULLY OPEN
3" OPEN
2" OPEN
3/4" OPEN LP
10'
0'
1" OPEN NG
6'
8'
10'
12'
14'
16'
18'
20'
Fig. #44a
OPENING
27
TC36.COD 102513-40
Vent Restrictor Adjustment
