4-Way Valve Reversing Failure.....................................................................................................................................1

Communication Error Between Indoor And Oudtoor Unit............................................................................................9

Communication Error Between Power Module And Pcb.........................................................................................18

Compressor Start Failure..........................................................................................................................................27

Dc Fan Motor Failure.................................................................................................................................................34

High Pressure Switch Off Failure................................................................................................................................40

Indoor Unit Overload.................................................................................................................................................52

Temperature Sensor Failure......................................................................................................................................62

Part 2. MRV 5 series trouble shooting

1.Trouble Shooting

Commnunication Between Indoor And Wired Controller Failure..................................................................................70

Communication Between Dc Fan Motor And Indoor Pcb Failure...............................................................................79

Communication Between Indoor And Display Board Failure.......................................................................................82

Dc Fan Motor Failure.................................................................................................................................................89

Dc Motor Model Is Wrong.........................................................................................................................................95

Fan Module Commnication Failure............................................................................................................................98

Fan Module Hardware Overcurrent.........................................................................................................................103

Indoor Address Repeated Failure.............................................................................................................................110

Indoor Eeprom Failure.........................................................................................................................................115

Indoor Float Switch Failure.......................................................................................................................................120

Indoor Temperature Sensor Failure..........................................................................................................................128

Indoor Unit 50Hz Zero-Crossing Failure...................................................................................................................138

Power Module Commnication Failure......................................................................................................................144

Power Module Hardware Overcurrent.....................................................................................................................149

The Compressor Out Of Control...............................................................................................................................157

Troubleshooting For 4-Way Valve Reversing Failure..................................................................................................164

Troubleshooting For Mrv 5 Indoor And Outdoor Communication Failure..................................................................175

Troubleshooting For Outdoor Temperature Sensor Failure........................................................................................188

Troubleshooting For The Compressor Startup Failure................................................................................................201

2. Part inspection

MRV 5 outdoor fan motor inspection......................................................................................................................207

Mrv 5 Power Module Inspection...........................................................................................................................210

Content