23
M1M operating Instructions
(Direct Ignition Furnaces)
Direct ignition furnaces do not have a pilot. Ignition is
accomplished by a silicon carbide hot surface ignitor. A
control module takes care of all timing functions. After
lighting, the control module uses the ignitor as a flame
sensor, shutting off gas should the flame go out. 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. Set the thermostat to the lowest setting.
2. Turn off all electric power to the appliance.
3. Remove the furnace door and turn off the gas valve:
•
Honeywell: push in and turn the gas control knob
clockwise to
OFF
. See
.
•
Robertshaw: push the gas control lever
(Do not force!)
to the
OFF
position. See
.
4. Wait ten (10) minutes to clear out any gas. If you smell
gas,
stoP!
and follow the Safety Information on
. If you do not smell gas, proceed to next step 5.
5. Set the thermostat MODE the
ON
position.
6. Turn the gas valve ON:
•
Honeywell: push in and turn gas control knob counter-
clockwise to
ON
(
•
Robertshaw: push the gas control lever to the
ON
position
).
Do not force!
7. Replace the furnace door.
8. Turn on all electric power to the appliance.
9. Change the thermostat mode to
HEat
and the
temperature selector to a desired temperature level.
The igniter should light in approximately 75 seconds.
If the appliance will not operate, see
and call your service technician or
gas supplier.
notE: In the event of any flashback or explosion,
immediately shut off the furnace and call your service
technician.
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 On-Off Switch to
OFF
.
• Honeywell (
): Turn gas control knob clockwise
to
OFF
, Robertshaw (
): Push the gas control
lever to
OFF.
• For oil, shut off all valves.
4. Replace the furnace door.
M5s operating Instructions
(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 fire door is closed.
3. Set the furnace On-Off switch to
ON
.
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
Replacement Parts List.
M1B operating Instructions
(Gas Gun Furnaces)
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 floor because some gases are
heavier than air and will settle on the floor.
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
).
•
Robertshaw: push the gas control lever to
OFF
(
).The lever cannot be placed in the off position unless
it is pushed in slightly.
Do not FoRcE!
Figure 30
Figure 30. Direct Ignition Gas Valve - Honeywell
GAS CONTROL KNOB
Figure 31
Gas Control Lever
Figure 31. Direct Ignition Gas Valve - Robertshaw
