[ IX Troubleshooting ]
- 259 -
HWE09080 GB
1. Error Code
Return air temperature sensor (TH21) fault (Indoor unit)
Return air temperature sensor (TH4) fault (OA processing unit)
Pipe temperature sensor (TH22) fault (Indoor unit)
Pipe temperature sensor (TH2) fault (OA processing unit)
Gas-side pipe temperature sensor (TH23) fault (Indoor unit)
Gas-side pipe temperature sensor (TH3) fault (OA processing unit)
Intake air temperature sensor (TH1) fault (OA processing unit)
Intake air temperature sensor (TH24) fault (All-fresh (100% outdoor air) type indoor unit)
2. Error definition and error detection method
If a short or an open is detected during thermostat ON, the heat source unit turns to anti-restart mode for 3 minutes. When
the error is not restored after 3 minutes (if restored, the heat source unit runs normally), the heat source unit makes an error
stop.
Short: detectable at 90°C [194°F] or higher
Open: detectable at -40°C [-40°F] or lower
Sensor error at gas-side cannot be detected under the following conditions.
During heating operation
During cooling operation for 3 minutes after the compressor turns on.
3. Cause, check method and remedy
5101
5102
5103
5104
Cause Check method and remedy
(1) Thermistor failure Check the thermistor resistor.
0°C [32°F]: 15 kohm
10°C [50°F]: 9.7 kohm
20°C [68°F] : 6.4 kohm
30°C [86°F] : 4.3 kohm
40°C [104°F] : 3.1 kohm
(2) Connector contact failure
(3) Disconnected wire or partial disconnected
thermistor wire
(4) Unattached thermistor or contact failure
(5) Indoor board (detection circuit) failure Check the connector contact.
When no fault is found, the indoor board is a failure.