55
No. Caused by (outdoor unit)
LED lamps
Meaning
2 3 4 5
— Normal ●● ●● ●● ●● Normal operation
— Defective in IC chip (E
2
PROM) ●● ●● ●● ● Cannot read IC chip data or missing IC chip on outside
PCB
— Defective Gas Valves ●● ●● ● ●● Detects abnormality in Gas Valve Circuit at initial
checking
A Detective Thermistor 1 ●● ●● ●● Open or Short of Thermistor 1
B Detective Thermistor 2 ●● ● ●● ●● Open or Short of Thermistor 2
C Limit switch ●● ● ●● ● Thermal fuse or Bimetal Thermostat tripped
D Flame current circuit ●● ● ● ●● Defective abnormal in Flame Current Circuit
E Lighting failure ●● ● ● ● Couldn’t establish flame
F Lost flame ● ●● ●● ●● Flame Sensor Circuit detects lost flame and could not
establish the flame
G Incorrect combustion motor speed ● ●● ●● ● Incorrect combustion motor speed
H Over-time period in retry ● ●● ● ●● Thermistor 1 or Thermistor 2 temperature did not go
down in set period
I Over number of times in retry ● ●● ●● Combustion stopped by Thermistor 1 or Thermistor 2
more than set number
J Bypass Valve (V2) not open ● ● ●● ●● Bypass Valve failure or drop-out of Thermistor 2
— Reversing Valve not working ● ● ●● ● Reversing Valve failure, drop-out of Thermistor 2, or
shortage of refrigerant
12-3-2. Thermistor Abnormality (Indoor Unit Only)
Check open / short circuit at the coil thermistor and room thermistor (between 1 and 2 of the lamp 8P) on the
PCB of the indoor unit (but only when the room temperature is 14 to 113°F).
12-3-3. Protective Circuit of Outdoor (Burner) Unit Operated
Check the following according to the failure display. Check items listed in 12-6. Heating Operation Not Possible.
12-3-4. CT Detection (Refer to 12-3-9 and 12-3-10.)
(1) Compressor abnormality
(2) Compressor over-load relay engaged
Note: Refer to 12-8. Failure Display on Outdoor Unit and Correction Method.
●● light off
● light on
