20
If the furnace fails to operate check the following:
• Is the thermostat operating properly?
• Are the blower compartment door(s) in place?
• Is the furnace disconnect closed?
• Has the circuit breaker tripped or the control board fuse burned
open?
• Is the gas turned on?
• Are any manual reset switches open?
• Is the fi lter dirty or plugged?
• Is the fl ame sensor coated? (Remove and clean with steel wool).
• Are all the LED’s on the furnace control board constantly ON? If
not, refer to Tables 3 - 4 or the wiring diagram (Figure 17, page
24) to determine fault condition
IMPORTANT NOTE: The furnace will lock out after 5 failed
attempts for ignition and will try again every hour if the call
for heat remains.
• If the Inducer Blower is operating, and items above have been
verifi ed, check the Blower Limit Switch (Figure 18, page 27) and
reset if necessary.
• If the furnace operates when the Blower Limit Switch is reset,
contact a qualifi ed service technician to identify and repair the
problem.
• If the furnace still doesn’t operate, check the Flame Roll-out
Switches (Figure 18, page 27) and reset if necessary.
• If the furnace operates when the Flame Rollout Switch is reset,
contact a qualifi ed service technician to identify and repair the
problem.
Diagnostic Description
Green
LED
Red
LED
Control Fault (No Power)
Off
Off
L1/Neutral Polarity Fault
Flash
Flash
1 Hour Lockout
Alternating Flash
Normal Operation
On
On
Pressure Switch Closed Fault
On
Flash
Pressure Switch Open Fault
Flash
On
Open Limit Switch Fault
Flash
Off
Diagnostic Description
Yellow LED
Low Flame Sensor Signal
Continuous Flash
Flame Present
On
Table 3. Furnace Control Board
Fault Conditions
Diagnostic Description
Red
LED
Green
LED
Control Fault (No Power)
Off
Off
Normal Operation
On
On
Motor Fault
On
Flash
Twin Fault (no motor fault)
Flash
On
Communications Fault
Flash
Flash
Table 4. Motor Control Board
Fault Conditions
TROUBLESHOOTING
Содержание G7XA Series
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