23
COMPONENT FUNCTIONS
Flame Roll-Out Control
The fl ame roll-out control acts to verify that the burner
fl ame is being drawn into the heat exchanger tubes. If the
burner fl ame is not being drawn into the heat exchanger
tubes, the roll-out control will open within several seconds
and the integrated control diagnostic light will fl ash one
time. The circulating air blower and combustion blower
will continue to operate if the fl ame roll-out control opens.
Flame Sensor
The fl ame sensor acts to prove that fl ame has carried
over from the ignitor to the right-most burner. If no fl ame
is sensed, the unit will be shut down automatically.
Gas Valve
The gas valve controls the fl ow of gas to the burners in
both low and high fi re. When the gas valve is energized
it automatically opens and regulates the gas pressure in
the manifold.
Pressure Switch
The pressure switch verifi es that the inducer motor is
drawing the combustion gases through the heat exchanger
tubes and venting the gases through the vent system.
Over-Temperature Limit Control
The over-temperature limit control prevents the air
temperature leaving the unit from exceeding the maximum
outlet air temperature. If the limit opens, the integrated
control diagnostic will fl ash one time. The circulating air
blower and combustion blower will continue to operate if
the over-temperature limit control opens.
TROUBLESHOOTING
If the unit does not operate in the cooling mode, check
the following:
• The thermostat is operating properly
• Electrical power to the unit is turned on
• The fi lters are not dirty
• The service doors are in place
• The 3 amp fuse is operational
If the unit does not operate in the heating mode, check
the following:
• The thermostat is operating properly
• Electrical power to the unit is turned on
• The fi lters are not dirty
• The gas is turned on and the manual shut-off valve
is open
• The service doors are in place
• The fl ame roll-out control is closed
• The diagnostic codes listed in Table 7 or on the wiring
diagrams (Figures 12 or 13, pages 28 - 29).
• The 5 amp fuse is operational
Table 8. Diagnostic Codes
STATUS LIGHT
(Red LED)
FAULT CONDITION
On
Power On
1 Flash
Limit Circuit Open
2 Flashes
Pressure Switch Stuck Open
3 Flashes
Pressure Switch Stuck Closed
4 Flashes
Ignition Failure (Check Ground)
5 Flashes
230 VAC & Neutral Reversed or
no ground
Continuous Flash
False Flame or Gas Relay Shorted
Off
Power Off
STATUS LIGHT
(Yellow LED)
FAULT CONDITION
Continuous Flash
Low Flame Sensor Signal
On
Flame Present
REPLACEMENT PARTS
Replacement parts are available through all Nordyne
distributors. Please have the complete model and serial
number of the unit when ordering replacement parts.
ELECTRICAL:
Capacitors
Pressure Switches
Compressors
Relays
Contactors
Temperature Limit Switches
Gas Valves
Thermostats
Ignition Controls
Time Delay Relays
Ignitors/Flame Sensors
Transformers
MOTORS:
Blower Motor
Fan Motor
Inducer Blower Motor
COMPONENTS:
Blower Assembly
Fan Grille
Burner Manifold
Filter/Driers
Burners/Orifi ces
Gaskets
Cabinet Panels
Heat Exchanger
Expansion Valves
