Nordyne Forced Air Gas and Oil Furnace M1M - Manual (Page 24)

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accomplished automatically by a silicon car-
bide 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 manually.
The control module is not field serviceable.
1. Before operation, smell all around the fur-
nace for gas. Be sure to smell next to the
floor because some gas is heavier than air
and will settle on the floor. If you smell gas,
STOP! and follow the safety instructions
below. If you don’t smell gas, go to the next
step.
2. Set the thermostat to the lowest setting.
3. Turn off all electric power to the appliance.
4. This appliance is equipped with an ignition
device which automatically lights the burner.
Do not try to light the burner by hand.
5. Honeywell - push in the gas control knob
and turn clockwise to “OFF.” Robertshaw
- push the gas control lever to “OFF.”
NOTE: The lever cannot be placed in the
“OFF” position unless it is pushed in slightly.
DO NOT FORCE (See Figures 30 & 31).
6. Wait ten minutes to clear out any gas. If you
then smell gas, STOP! and follow the safety
information on the preceding page. If you
don’t smell gas, go to the next step.
7. Set the On-Off switch to the “ON” position.
8. Honeywell - turn knob on gas control counter
clockwise to “ON.” Robertshaw - push the
gas control lever to “ON.”
9. Turn on the electric power to the appliance.
10. 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 “To Turn Off Gas To Appli-
ance” and call your service technician or
gas supplier.
In the event of any flashback or explosion,
immediately shut off the furnace and call
your service technician.
SEQUENCE OF OPERATION FOR
GAS GUN MODELS
a. On a call for heat, the furnace control begins
an ignition sequence which lasts approxi-
mately 45 seconds.
b. After this sequence, the control module tests
to see if flame is sensed. If it has, the furnace
continues to heat until the thermostat is
satisfied.
c. If the burner has not lit, the ignition sequence
is repeated a maximum of two more times. If
flame is not sensed after three attempts, the
control enters “Lockout” and no further at-
tempts to light the burner will occur. If
“Lockout” occurs, contact a qualified service
technician for assistance.
! DANGER:
Before placing the furnace in service
it must be checked to make sure it is
equipped for the type of gas being
used. The burner flame must also be
observed and adjusted if necessary.
Failure to observe this caution may
result in unsafe operation, explosion
and/or fire, or asphyxiation. See the
following sections “Gas Supply” and
“Combustion Air.”
d. When call for heat is satisfied, the thermostat
contacts open and the gas valve shuts off
gas flow.
TO TURN OFF GAS/OIL APPLIANCE:
a. Set the thermostat to the lowest setting.
b. Turn off all electric power to the appliance
before servicing unit.
c. Set the On-Off Switch to “OFF.”
d. Honeywell - turn gas control knob clockwise
to “OFF” Robertshaw - Push the gas control
lever to “OFF.”
e. For oil, shut off all valves.
f. Replace the furnace door.
THE FURNACE CONTROLS AND FUNC-
TIONS
1. On-Off Switch - This switch turns electrical
power to the furnace on and off. The switch
must be set in the “On” position for the
furnace to operate. For M1G* models, in
warm weather there is a possibility of the
blower coming on periodically or operating
continuously due to a heat buildup within the
furnace by a combination of warm weather
and heat from the pilot. This is normal
operation as long as there is power to the
furnace and the On-Off switch is at the “ON”
position. If blower operation is not desired,
the On-Off switch may be set in the “OFF”
position to cut the electrical power to the
furnace.