Whether the resistance of the room temp. sensor is 10K

• No

  Replace room temp. sensor

• Yes

  Replace indoor PCB

Whether the resistance of the evaporator temp. sensor is 10K

• No

  Replace evaporator temp. sensor

• Yes

  Replace indoor PCB

Whether the outdoor unit is power on

• No

  Check when the power is on

• Yes

  Measure whether the voltage of the communication line’s red and black end between the indoor and outdoor unit is +5V

  • No

    Replace the outdoor unit board

  • Yes

    Check the indoor unit main board CN5 or replace the main control board

    • Yes

      Replace indoor PCB

EEPROM chip is broken

• Yes

  Replace EEPROM

• No

  Check whether the main control chip 9177 is broken

  • Yes

    Replace 9177 chip

  • No

    Check PCB board or replace the main control board

Check whether the water-level switch is inserted well

• No

  Insert the water-level switch well

• Yes

  Check whether the water-level switch is broken

  • Yes

    Replace the water-level switch

  • No

    Check whether the water pump is normal

    • No

      Replace the water pump

    • Yes

      Check PCB board or replace the main control board

Change the order of two of the wires to power supply.

• Yes

  Switch on the unit again

  • Yes

    If the problem can not be solved, the outdoor PCB is defective

Check the current, normally Is the current in rated range?

• No

  Possible reason 1. Outdoor fan is defective 2. The compressor is defective 3. Refrigerant is over charged 4. Air enter the refrigerant system 5. Heat exchanger is too dirty

• Yes

  The outdoor PCB is defective

Check the power supply, is it 3 phase, 380-415V?

• Yes

  Check the connection between power supply and terminal, is the voltage in outdoor terminal is 3 phase, 380-415V?

  • Yes

    Outdoor PCB is defective

Is it k1 or K2 open ?

• K1

  Is temp. protective switch K1 open

  • Yes

    Possible reason 1. The wires is loose to K1 2. Air or other gas in the refrigerant. 3. Heat exchanger is dirty 4. Outdoor fan or fan blade is defective 5. Outdoor unit is bad ventilation 6. Refrigerant is leakage 7. K1 switch is defective

• K2

  Is pressure protective switch K2 open

  • Yes

    Possible reason 1. The wires is loose to K2 2. Air or other gas in the refrigerant. 3. Heat exchanger is dirty 4. Outdoor fan or fan blade is defective 5. Outdoor unit is bad ventilation 6. Refrigerant is two much 7. K2 switch is defective

Repair connector

Check the resistance of the temp. sensor according to Annex 1

• Yes

  Is it the resistance is normal?

  • No

    Replace the sensor

  • Yes

    Outdoor PCB is defective

Repair connector

Check the resistance of the temp. sensor according to Annex 1

• Yes

  Is it the resistance is normal?

  • No

    Replace the sensor

  • Yes

    Outdoor PCB is defective

Check the resistance of the temp. sensor according to Annex 1, is it normal?

• No

  Replace the sensor

• Yes

  Possible reason 1. Air or other gas in the refrigerant. 2. Heat exchanger is dirty 3. Outdoor fan or fan blade is defective 4. Outdoor unit is bad ventilation 5. Refrigerant is leakage 6. Outdoor PCB is defective