|LED is steadily on
||Normal fault detected.
|Single LED flash
||Failed to detect flame within three attempts for ignition, 1-hour lockout.
|Two LED flashes
||The pressure switch is stuck open or induced draft blower problem detected.
||Try to manually close the switch, replace the switch, or check blowers and vents for air pressure.
|Three LED flashes
||The limit switch is open, or the roll-out control is engaged.
||Check for a restricted air vent, loose blower wheel, a defective blower, or a dirty air filter.
|Four LED flashes
||The pressure switch is stuck closed, or the switch won’t open.
||Check for an obstruction in the pressure tubing.
|Five LED flashes
|Six LED flashes
||Line and Neutral are reversed.
||Control board or the furnace’s ground could be defective.