Specifications
Table Of Contents
- Cover
- Table of Contents
- Part 1 List of Functions
- Part 2 Specifications
- Part 3 Printed Circuit Board Connector Wiring Diagram
- Part 4 Function and Control
- Part 5 Operation Manual
- Part 6 Service Diagnosis
- 1. Caution for Diagnosis
- 2. Problem Symptoms and Measures
- 3. Service Check Function
- 4. Code Indication on the Remote Controller
- 5. Troubleshooting
- 5.1 Indoor Units
- 5.2 Outdoor Units
- 5.3 Indoor Unit PCB Abnormality A1
- 5.4 Freeze-up Protection Control or High Pressure Control A5
- 5.5 Fan Motor or Related Abnormality A6
- 5.6 Thermistor or Related Abnormality (Indoor Unit) C4,C9
- 5.7 Front Panel Open / Close Fault C7
- 5.8 Signal Transmission Error (between Indoor and OutdoorUnit) U4
- 5.9 Unspecified Voltage (between Indoor and Outdoor Units) UA
- 5.10 Freeze-up Protection Control A5
- 5.11 Outdoor Unit PCB Abnormality E1
- 5.12 OL Activation (Compressor Overload) E5
- 5.13 Compressor Lock E6
- 5.14 DC Fan Lock E7
- 5.15 Input Over Current Detection E8
- 5.16 Discharge Pipe Temperature Control F3
- 5.17 High Pressure Control in Cooling F6
- 5.18 Compressor Sensor System Abnormality H0
- 5.19 Position Sensor Abnormality H6
- 5.20 CT or Related Abnormality H8
- 5.21 Thermistor or Related Abnormality (Outdoor Unit) P4,J3,J6,J8,J9,H9
- 5.22 Electrical Box Temperature Rise L3
- 5.23 Radiation Fin Temperature Rise L4
- 5.24 Output Over Current Detection L5
- 5.25 Insufficient Gas U0
- 5.26 Low-voltage Detection or Over-voltage Detection U2
- 5.27 Signal Transmission Error (on Outdoor Unit PCB) U7
- 5.28 Anti-icing Function in Other Rooms / UnspecifiedVoltage (between Indoor and Outdoor Units) UA,UH
- 6. Check
- Part 7 Removal Procedure
- Part 8 Others
- Part 9 Appendix
- Index
- Drawings & Flow Charts

SiBE12-713 Troubleshooting
Service Diagnosis 237
5.4 Freeze-up Protection Control or High Pressure Control
Remote
Controller
Display
A5
Method of
Malfunction
Detection
High pressure control (heat pump model only)
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is used for the high pressure control (stop, outdoor fan stop, etc.)
The freeze-up protection control (operation halt) is activated during cooling operation
according to the temperature detected by the indoor unit heat exchanger thermistor.
Malfunction
Decision
Conditions
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is above 65°C
Freeze-up protection
When the indoor unit heat exchanger temperature is below 0°C during cooling operation.
Supposed
Causes
Operation halt due to clogged air filter of the indoor unit.
Operation halt due to dust accumulation on the indoor unit heat exchanger.
Operation halt due to short-circuit.
Detection error due to faulty indoor unit heat exchanger thermistor.
Detection error due to faulty indoor unit PCB.