How to Shut Off Gas - Direct Ignition
1.Set the thermostat to the lowest setting.
2.Turn off all electric power to the appliance before servicing unit.
3.Set the furnace
•Honeywell (Figure 32):Turn gas control knob clockwise to OFF, Robertshaw (Figure 33): Push the gas control lever to OFF.
•For oil, shut off all valves.
4.Replace the furnace door.
Operating Instructions for Oil Gun Furnaces If your furnace model number begins with M5S*, the furnace is equipped with an ignition device which automatically lights the burner. Do not try to light this furnace manually.
1.Open all valves in the oil line.
2.Verify the fi re door is closed.
3.Set the furnace
4.Set the thermostat to the desired setting.
NOTE: M5 oil gun furnaces may be converted to gas gun in the field by using the proper conversion kit listed in the RPL.
Operating Instructions for Gas Gun Models If your furnace model number begins with M1B, the furnace does not have a pilot. Ignition is accomplished by a silicon carbide hot surface ignitor. A control module takes care of all lighting and timing functions. There are no external relays or timing devices. Do not try to light this furnace by hand. The control module is not field serviceable.
1.Before operation, smell for gas all around the furnace, especially near the fl oor because some gases are heavier than air and will settle on the fl oor.If you detect gas, STOP and follow all the safety instructions.
2.Set the thermostat to the lowest setting.
3.Turn off all electric power to the appliance.
4.Turn off the gas valve:
•Honeywell: push in the gas control knob and turn clockwise to OFF (Figure 32).
•Robertshaw: push the gas control lever to OFF (Figure 33).The lever cannot be placed in the off position unless it is pushed in slightly. DO NOT FORCE!
5.Wait ten minutes to clear out any gas. If you smell gas, STOP! and follow the safety information. If gas is not detected, proceed to the next step.
6.Set the furnace
•Honeywell:turn knob on gas control counter clockwise to ON.
•Robertshaw: push the gas control lever to ON.
7.Turn electric power to the appliance ON.
8.Set the thermostat to HEAT and/or the desired temperature setting. The furnace should light in approximately 45 seconds. If the appliance will not operate, follow the instructions “How to Shut Off Gas - Direct Ignition Furnace” (page
21)and call your service technician or gas supplier.
In the event of any fl ashback or explosion, immediately shut off the furnace and call your service technician.
How to Shut Off Gas - Oil & Gas Gun
1.Set the thermostat to the lowest setting.
2.Turn off all electric power to the appliance at the breaker or fuse box.
3.Set the thermostat MODE switch to OFF.
4.Turn the gas valve OFF:
•Honeywell: push in and turn the gas control knob clockwise to the OFF position (Figure 32).
•Robertshaw - push the gas control lever to the OFF position (Figure 33).
5.Replace the furnace door.
NOTE: M1B gas gun furnaces may be converted to oil gun in the fi eld by using the proper conversion kit listed in the RPL
Burner Adjustments
Burner settings are made at the factory.However, these settings may change during shipping, handling, and installation. The following items should be checked and readjusted if necessary.
Gas Pressure
The gas pressure can be checked with a manometer at the pressure tap located on the side of the gas valve. The gas valve pressure regulator can be adjusted by removing the regulator selector stack and turning the slotted insert located directly under the selector stack. The regulator selector stack must be secured in place before each pressure reading is taken. Natural gas manifold pressure should be 3.5” W.C. and L.P. gas manifold pressure should be 10” W.C. Replace the gas pressure tap plug on the gas valve.
Pilot Flame (Standing Pilot Only)
The pilot fl ame can be adjusted by turning the pilot adjustment screw, located on top of the gas valve (See Figure 30, page 20). The pilot
flame height should be between 3/4” and 1.” The
flame tip should be visible just above the pilot bracket when viewed through the observation door. The same pilot orifi ce is used with both natural and LP gas.
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