38
SERVICE GUIDE
LED CODES
STATUS
CONTINUOUS OFF
No 24 VAC Power to Control.
FLASHING (RED, AMBER, GREEN)
Power--up verification of LED.
CONTINUOUS ON (RED)
Internal Control Fault Detected, control will try to Auto--Reset, power cycle recommended.
Replace control if power cycle doesn’t correct fault.
CONTINUOUS ON (GREEN)
Standby, Normal Operation, No Thermostat Requests.
RAPID FLASHING (RED)
Line voltage (115VAC) polarity reversed.
RAPID FLASHING (GREEN)
Clear Error History
.
EACH OF THE FOLLOWING STATUS CODES IS A COMBINATION OF A SERIES OF FLASHES WITH A
SPECIFIC COLOR LED
COMPONENT TEST
LED ACTIVITY (CFH = Call for Heat)
1 FLASH (RED)
System Lockout: Retries Exceeded, 1 Hour Fixed. Retries are defined as failed ignition attempts,
i.e. no flame sense during the trial for ignition period. Recycles are defined as loss of flame after flame has been
established during the trial for ignition period, and there is no limit to the number of recycles.
Check for no gas or gas valve OFF, broken or disconnected igniter, broken or disconnected or shorted flame
sensor. Burner box air leak at igniter or flame sensor or main gasket.
2 FLASHES (RED)
Pressure Sensor Null Error: Inconsistent reading with inducer off, 5 second lockout, Unlimited Retries.
Control waits 5 seconds after CFH before displaying fault. Fault is displayed until fault condition corrects or
CFH is removed.
Check:
Pressure Tube and Vent for restriction9s), Transducer electrical/pressure connections,
Inducer wheel and motor move freely. Ensure pressure tube not covering bleed port on transducer.
3 FLASHES (RED
)
Pressure Sensor Span Error: Inconsistent reading with inducer on, 5 minute lockout, Unlimited Retries.
Span test maximum duration is 90 seconds. Once the span test fails, the control continues to attempt to start
furnace and fault is displayed until fault condition corrects or CFH is removed.
Check:
Inducer not operating,
Transducer tube disconnected, broken or leaking, covering bleed port of transducer, vent for restrictions.
Minimum pressure not reached.
4 FLASHES (RED)
Main Limit Circuit Open: 3 hour lock out.
When an open limit is detected, the control energizes the blower at heating speed -- no CFH required. Once the
limit closes and the CFH is present, the furnace returns to normal operation.
Check:
Main limit, Draft
Safeguard, Burner Thermal Switch are all in the Main Limit Circuit. Check for any blockages in flue pipe or
blower airside restrictions like dirty filter, blocked inlet to burner or restriction in burner box that was pulled in
through the air inlet.
5 FLASHES (RED
)
Flame Present with Gas Valve OFF. When detected, the control energizes the inducer at the ”Run” setting, and
displays fault -- no CFH required. Control continues normal operation when fault condition is corrected.
Check:
for leaking gas valve. A shorted flame sensor to ground will
NOT
cause this fault to occur.
6 FLASHES (RED)
Auxiliary Limit Open: 3 hour lockout. When detected, the control energizes the blower at heating speed and
displays fault -- no CFH required. Control continues normal operation when fault condition is corrected.
Check:
blower operation,these switches will usually open during a no blower operation case, in horizontal or
downflow installation.
7 FLASHES (RED)
Gas Valve Circuit Shorted: 1 hour Lockout. Voltage sensed at the gas valve terminal with the safety relay in the
de--energized state. The inducer is energized to maximum speed until corrected or 24V removed.
LED ACTIVITY
1 FLASH (AMBER)
Low Flame Sense. Flame Sense Current is below the weak flame threshold [3.0
μ
Amp].
A poor or no ground can cause this fault as well as a dirty or corroded sensor.
2 FLASHES (AMBER
)
ID Plug Failure: Operation continues after fault correction. Wrong values for the specific board.
Includes damaged ID plug, ID plug missing.
3 FLASHES (AMBER)
Control Fuse Open: Operation continues after fault correction.
1 FLASH (GREEN)
Call for Heating. ”W” or ”W & G”.
2 FLASHES (GREEN
)
Call for Cooling. ”Y” or ”Y & G”.
3 FLASHES (GREEN)
Continuous Fan Operation. ”G” only.
FAULT RECALL AND CLEARING
Fault Code Recall (up to last 5)
The control must be powered and the thermostat satisfied (no call for heat or cool). Depress and release the SW1 button once
(less than 5 seconds); the LED will flash the Fault Code History (up to 5 fault codes from newest to oldest).
Fault Code Clear
The control must be powered and the thermostat satisfied (no call for heat or cool). Depress and hold the SW1 button for at least
5 seconds (but not more than 10 seconds), until the LED flashes a rapid green, then release. The fault code history will be erased.
If the button is pressed longer than 10 seconds, a power reset may be required to resume normal operation.
