VENT SYSTEM
After the floor furnace has been burning for five minutes, hold a match or candle under the draft hood at the air intake area. If the vent system is working properly, the flame will be pulled into the air inlet of the draft hood. If the vent system is not working properly, turn the floor furnace off immediately and refer to the installation instructions or local code for proper installation procedure.
PILOT FLAME ADJUSTMENT Pilot flame should envelop 3/8 to 1/2 inch of the tip of the generator.
3/8 to 1/2”
FIGURE 17
ADJUSTING THE PILOT FLAME
Refer to Figure 17 for the correct size pilot flame. If adjustment is necessary, refer to Figure 12 for the location of the pilot adjustment screw. Using a standard screwdriver, remove the pilot adjustment screw cover. Insert a
small screwdriver into the pilot adjustment screw and turn clockwise 
to
decrease the flame or counterclockwise 
to increase the flame. If the flame is too low, the safety pilot may cause all of the gas to be cut off. NOTE: The gas supply to the pilot is unregulated. When line pressure exceeds 7” Natural Gas, or 11” L.P. Gas, a pilot adjustment must be made.
BURNER ORIFICE
This appliance is orificed at the factory for elevations up to 2,000 feet. If installed above 2,000 feet, the BTU input must be reduced 4% per 1,000 feet. See the following orifice chart for the proper orifice for a specific elevation.
NATURAL GAS
SPECIFICELEVATIONS
Model No. | 0 to | 2,000 - | 4,000 - | 6,000 - | 8,000 – |
| 2,000’ 4,000’ | 6,000’ | 8,000’ | 10,000’ | |
90N30A | 38 | 41 | 42 | 43 | 44 |
90N50A | 30 | 31 | 31 | 32 | 35 |
90N65A | 26 | 28 | 29 | 30 | 30 |
ORDER KIT #49800 | |||||
90N75A | 33 | 36 | 37 | 38 | 41 |
ORDER KIT #49850
L.P. GAS
SPECIFICELEVATIONS
Model No. | 0 to | 2,000 - | 4,000 - | 6,000 - | 8,000– |
| 2,000’ | 4,000’ | 6,000’ | 8,000’ | 10,000’ |
90P30A | 1/16 | 53 | 53 | 54 | 54 |
90P50A | 47 | 49 | 49 | 50 | 51 |
90P65A | 43 | 44 | 45 | 47 | 48 |
ORDER KIT #49800 | |||||
90P75A | 51 | 52 | 52 | 53 | 54 |
ORDER KIT #49850
ADJUSTING THE BURNER
After the floor furnace has been burning 15 minutes, remove the bottom pan from the outer casing exposing the complete burner assembly. Loosen the screw at the bottom side of the sliding air shutter. Slide the air shutter closed until yellow tips start to appear at the top of the flame. See Figure 19. (75,000 BTU floor furnace has two burners, both of which may need adjustment). Now open the shutter slightly beyond the point that the yellow disappears and the flame burns blue. (See Figure 20). Airborne dust particles may cause flashes or streaks of yellow flame as they are drawn into the flame but will have no effect on the efficiency of the floor furnace. If you are satisfied that the burner is properly adjusted, tighten the set screw to lock the shutter in position. Replace the bottom pan. Check air shutter setting at least twice each season to assure that changing conditions are not causing yellow tipping.
Sliding Air Shutter
BURNER
Set Screw
Manifold Tube
YELLOW
IMPROPER FLAME ADJUSTMENT
BLUE
CORRECT FLAME ADJUSTMENT
FIGURE 18 | FIGURE 19 | FIGURE 20 |
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