Combustion Air

In order for the fl ame to burn effi ciently, it must receive adequate combustion air. The amount of combustion air required varies according to altitude, actual B.T.U. content of the fuel, gas pressure, conversion to another gas and other factors. The burner fl ame should be observed and any necessary adjustments made before the furnace is placed into service. See Table 7 for Factory Air settings.

CAUTION:

Combustion air adjustment must be made only by a qualified tech- nician. Improper air adjustment may cause unsafe operation, ex- plosion and/or fire asphyxiation.

If the input to the furnace is too great because of excessive gas pressure, wrong size nozzle or orifice, high altitude, etc., the burner flame will be sooty and can produce carbon monoxide, which could result in unsafe operation, explosion and/or fire or asphyxiation.

Model

Nat. Gas

LP Gas

Oil

 

 

 

 

66,000

3.5

3.5

3.5

 

 

 

 

86,000

5.3

6

5

Table 7. Factory Combustion Air Settings

Gas Gun

Combustion air box adjustment is made to the main burner by loosening the two lock nuts on the plastic air shutter, located on the left side of the burner blower housing.Air shutter adjustment line is located on the same side of the blower housing. Turn the plastic shutter to a smaller number (counter clockwise) for less air to a larger number (clockwise) for more air. Gently tighten the lock nuts after completing the adjustment.For best results, use instrument to measure between 8 - 9% CO2, after the combustion air has been adjusted.Note: Do not over-tighten the lock nuts. This may damage the plastic air shutter.

Oil Gun Only

It is recommended that the CO2 and Smoke levels be measured for maximum performance. CO2 readings should be 10 - 11% for 66,000 BTUH furnaces and 12 - 13% for 86,000 BTUH furnaces.

The Smoke should be N0. 0 on the Bacharach Scale, and 0 to 0.02 negative draft over fi re.

Electrode Setting (Oil Gun Only)

Poor ignition of the oil spray may result if the electrodes are not adjusted as shown in Figure

34.Do not permit any electrodes to be grounded to any surface.

Switching Ignition Control between Interrupted and Intermittent Duty (Oil Gun Only)

Honeywell and Beckett oil primary controls can be switched between interrupted and intermittent ignition control. To switch from interrupted duty (Factory set) to intermittent duty, remove the blue wire from the quick-connect terminal. Attach the burner motor and igniter wire to the burner motor (orange) control terminal by splicing or adding tab adapters. Seal and isolate any bare wires.

5/32” GAP

ELECTRODE

5/16” ABOVE CL

NOZZLE

0-1/16”

1 1/8”

Figure 34. Oil Gun electrode Position

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Nordyne AND M5S, SERIES M1B installation instructions Factory Combustion Air Settings, Electrode Setting Oil Gun Only