Instructions / Assembly

23
burner motor (orange) control terminal by splicing or
adding tab adapters. Seal and isolate any bare wires.
See Figure 16.
Firing Rate Conversion
The rated fi ring rates of the CMF2 80 convertible furnaces
(PO & PG) can be adjusted from the factory setting of
75,000 BTU/hr. The fi ring rate can be changed to either
65,000 BTU/hr or to 85,000 BTU/hr using the appropriate
certifi ed NORDYNE conversion kit installed by a NORDYNE
distributor or Service PRO. See the Replacement Parts
Listing for the appropriate kit number to order.
Figure 16. PO Oil Burner Electrode Settings
5/32” GAP
ELECTRODE
NOZZLE
0-1/16”
5/16” ABOVE CL
1 1/8”
OPERATING SEQUENCE
PG Gas Furnaces
1. The thermostat calls for heat by energizing the W
terminal with 24 volts.
2. The combustion blower motor energizes. After the
motor begins to rotate, the centrifugal switch (located
in the motor end cap) closes.
3. A 30 second pre-purge period begins and the ignition
control initiates an internal safety start check.
4. If ignition control passes the safety check, a 15 second
ignitor warm-up period begins. During this period, the
ignitor warms up to an ignition temperature.
5. The control applies 24 volts to the gas valve.
6. The ignitor ignites the gas, and the presence of fl ame
must be detected within a timed trial ignition period.
NOTE: If fl ame is detected, the ignitor is de-energized
and the gas valve will remain open until the call for
heat from the thermostat is completed. If the fl ame
is not detected, the control will close the gas valve at
the end of the timed trial ignition period. The control
will attempt ignition 2 more times before locking out.
7. The circulating air blower will energize when the
temperature fan switch closes.
8. When the thermostat demand for heat is satisfi ed, the
W terminal de-energizes the gas valve circuit and the
gas valve will close.
9. The circulating air blower will de-energize when the
temperature fan switch opens.
NOTES:
• The control will close the gas valve if the fl ame sensor
does not detect the presence of a fl ame. The control will
attempt to re-ignite the gas 2 times before locking out.
If lock-out occurs, the control can be reset by setting
the thermostat below room temperature for at least 45
seconds, and then returning it to the desired setting.
If adjusting the thermostat does not reset the ignition
control, turn off all power to the appliance for 45 seconds,
and then turn it back on.
• If the gas control has been replaced or serviced, lighting
may not be satisfactory until air has been purged from
the gas line or the gas input and combustion air have
been adjusted.
PO Oil Furnaces
The processes listed below are applicable only to furnaces
equipped with a Honeywell R7184 or Beckett 7505 Control.
1. When a call for heat is initiated, there is a 2-6 second
delay while the control performs a safe start check.
2. The ignition and motor turn on for the 15 second valve
on delay. Following the delay, the valve energzes and
a fl ame should establish within a 15-second lockout
time.
NOTES:
• If fl ame is not sensed within the 15-second lockout time,
the control shuts down on safety lockout. The reset
button on the control must be manually reset.