3.4.
E2, E3, E4 Troubleshooting
3.4.1.
Display output
or
OPERATION LED
flashes twice per
second
or
OPERATION LED
flashes twice per
second
or
OPERATION LED
flashes twice per
second
3.4.2.
Description
▪
E2 indicates an indoor ambient temperature sensor error.
▪
E3 indicates an indoor heat exchanger mid-point temperature sensor error.
▪
E4 indicates an indoor heat exchanger outlet temperature sensor error.
3.4.3.
Impact on other units
▪
3.4.4.
Possible causes
▪
Temperature sensor not connected properly or has malfunctioned.
▪
Damaged main PCB.
3.4.5.
Procedure
E2 / E3 / E4
Temperature sensor connection on
main PCB is loose
1
Yes
Ensure the sensor is connected
properly
No
Temperature sensor has short-
circuited or failed
2
Yes
Replace the sensor
No
Replace indoor main PCB
Notes:
1.
The indoor ambient temperature sensor connection port, indoor heat exchanger mid-point temperature sensor connection port and indoor heat
exchanger outlet temperature sensor connection port on each type of indoor unit main PCB are labeled in Figures 1.1 to 1.19 in
1,
“
Main PCB Ports
”
.
2.
Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor
’
s resistance
characteristics table, the sensor has failed. Refer to Table 6.1 in
“Temperature Sensor Resistance Characteristics”
