Operating instructions

13
Venting
Restrictors
SOME INSTALLATIONS REQUIRE RESTRICTORS. For improved fl ame picture and
performance, this unit is supplied with two different sets of vent restrictors. The level of
restriction required depends on the vertical rise in the venting system and, to a lesser
degree, the horizontal run and number of elbows.
The amount of restriction is based on laboratory tests. The ideal restrictor position may
vary slightly, especially when the vent pipe length is near the limits of the acceptable
confi gurations for each type of restrictors.
The chart on the previous page shows the vent restrictor required relative to the length
of the vent pipe. Restrictors are not required for co-linear applications.
To install restrictors:
1. Remove every second screw from the exhaust ports in the top of the fi rebox.
2. Install the restrictors with the removed screws.
50
75
Restrictor 50 Restrictor 75
OR