Burner Flame Adjustments
SECTION 11
ADJUSTMENT
#BHM-38 & #BHM-38-BW
R.1 September 2021
71
HUSSONG MFG. CO., INC.
KOZY HEAT FIREPLACES
11.2 Burner Flame Adjustments
WARNING: To avoid property damage or personal injury, allow the
fireplace ample time to cool before making any adjustments.
Burner flame appearance and characteristics are affected by
altitude, fuel quality, venting configuration, and other factors. After
installation, this appliance may need additional adjustments to
achieve optimum flame appearance and visual aesthetics.
11.2.1 Burner Venturi
WARNING: VENTURI ADJUSTMENT MUST BE DONE BY A QUALIFIED
SERVICE TECHNICIAN.
When this appliance is first lit, the burner flames will appear blue.
During the first 15 minutes of operation, flame appearance will
gradually turn to the desired yellow appearance. If the flames remain
blue, or become dark orange with evidence of sooting (black tips),
adjustment of the air shutter opening may be necessary.
Regardless of venturi orientation, closing the air shutter will achieve a
desired yellow flame, but may produce soot on the glass. Opening the
air shutter will cause a short, blue flame that may lift off the burner.
Slight adjustments to the venturi opening will create dramatic results.
Adjust at slight increments until desired look is achieved.
NOTE: If soot is present on the logs, check log placement (section
8.4,
LOG SET INSTALLATION,
pg. 55) before adjustment.
Table 11.3, Factory Set Venturi Openings
Fuel
Front Burner Venturi
Rear Burner Venturi
Natural Gas
1/8” (3.175mm)
1/8” (3.175mm)
Propane
3/8” (9.525mm)
3/8” (9.525mm)
In the small components packet included with this appliance, there
is an air shutter adjustment tool to measure the factory set opening
for the sliding venturi shutters, as shown in
FIGURE 11.2
. Bend at the
pre-cut line to separate the natural gas and propane tools.
1. Remove the safety barrier screen, glass frame assembly and
media tray.
2. Remove the flange attached to the log rack, (5) screws. See
FIGURE 11.3.
3. Loosen the screws on the venturi brackets and adjust the venturi
as necessary. See flame adjustment guidelines in
FIGURE 11.4.
Re-tighten screws when finished.
Moving the sliding venturi shutter brackets(s) to the right
opens the air shutter opening and increases air.
Moving the sliding venturi shutter bracket(s) to the left closes
the air shutter opening and decreases air.
4. Reinstall all components previously removed.
Sliding venturi shutter
rear bracket - LEFT
Sliding venturi shutter
front bracket - RIGHT
Dark, orange flames with black tips
Short, blue flames
Lifting (ghosting) flames
Ideal Flame Appearance
Lazy, yellow flames - no adjustment necessary
Venturi(s) settings closed too far - open venturi(s) slightly
Venturi(s) open too far - close venturi(s) settings
Venturi(s) open too far - close venturi(s) slightly
Air shutter adjustment tool
Teeth to hold sliding air shutter
flange in place while securing
adjustment
1/8” for natural gas
venturi opening
3/8” for propane
venturi opening
FIGURE 11.2
Air shutter adjustment tool
FIGURE 11.3
Burner Venturis
FIGURE 11.4
Flame Appearance and Characteristics for Venturi Adjustment
