North American Evenglow 4723 Burners
BUILT-IN GAS ADJUSTMENT
The 4723 has a build in limiting orifi ce valve (LOV) for adjusting the gas fl ow. It is
located close to the fuel inlet on the backplate and has a cap that must be removed to
adjust the gas fl ow. The burner is shipped with the valve in the closed position. Turn
the screw counterclockwise to increase the fuel fl ow. Replace the cap aft er completing
fuel adjustments to discourage tampering with the gas setting.
For hot air systems the built in valve should be omitted because the internal seals are
not rated for high temperatures. The valve cartridge on the backplate is replaced with
a pipe plug. An external 1807 limiting orifi ce valve should then be piped as close as
practical to the burner.
PRIMARY AIR ADJUSTMENT
The primary air adjustment changes the amount of air premixed into the fuel. A set
20% of the combustion air is premixed with the gas even when the adjustment screw
is closed. The adjustment screw is located on the backplate opposite the gas inlet.
Turning the screw counterclockwise increases the amount of air premixed into the gas.
Increasing the air in the gas increases mixing and results in a shorter fl ame. Turning
the screw clockwise decreases the amount of air premixed into the gas, which delays
mixing and makes the fl ame longer.
No. Turns Open 30%
No. Turns Open 40%
SPARK LOCATION and GAP
The 4723- "E" model uses the North American 4-3681-1 spark igniter. During the igni-
tion period, a continuous 6000 volt spark is required. Spark distributor systems cannot
be used with 4723- -E Burners. The igniter should be placed in the burner so that the
ground leg of the igniter is facing towards the centerline of the burner (±90°). The ideal
spark gap for the 4723 is 0.063". Continuous operation of the igniter will reduce its life.
30% maximum primary air for -6 size.
‡ 32% maximum primary air for -4B size.
0.063 - 0.08
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