33
Diagnostic Chart
LED Indications: Flash Codes
Steady ON
OEM Test Mode
AMBER
Applying 24 VDC to the "G" terminal at power-
up places the control in OEM mode. Maximum
duration is 20 minutes.
1 Flash
Low Flame Sense
AMBER
Flame Sense Current is below the weak flame
threshold (<3 microamps)
2 Flashes
ID Plug Failure
AMBER
Wrong values for the specific board. Includes
damaged ID plug, ID plug missing, etc.
3 Flashes
Control Fuse Open
AMBER
Steady ON
Standby Normal Operation
No Thermostat Requests
GREEN
Rapid Flash
Clear Error History
GREEN
Press and hold the SW1 button for more than 5
seconds results in the display of this mode.
Releasing the Button during this indication will
cause the Error History to be cleared. The
button must be released within 5 seconds after
the LED begins this fla
3 Rapid Flashes
(On reset ONLY)
ID Plug Installed
GREEN
For controls with unit-specific programming
imbedded in the CPU, this indicates at power-
up that an valid ID Plug is installed and the
control will use the alternate parameters.
1 Flash
Call for Heating
GREEN
"W" or "W & G"
2 Flashes
Call for Cooling
GREEN
"Y" or "Y & G"
3 Flashes
Continuous Fan Operation
GREEN
"G" only
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Operation continues after
fault correction
Operation continues after
fault correction
