Greenheck IG / IGX (464104 IOM) (Pre-2009) - Manual (Page 55)

55
Operation - 4:1 Modulation & 8:1 Staged User Interface
Indicating Lights
Three indicating lights are located across the top of the display to indicate the status of the furnace.
4:1 Electronic Modulation
Light
On Off
L1 Call for Heat No Call for Heat
L2 Supply Fan On Supply Fan Off
L3 Freeze Protection Tripped Freeze Protection Satisfied
8:1 Staged Control (Single Furnace Units)
Light
On Blinking
L1 Call for Heat n/a
L2 n/a Furnace at High Fire
L3 Burner Locked Out Freeze Protection Tripped
8:1 Staged Control (Multi Furnace Units)
Light
On Blinking
L1 n/a n/a
L2 n/a Alarm
L3 Program Mode Saving New Settings
Operation