Shut off the power supply and turn it on 5 seconds later. Is it still displaying the error code?

• Yes

  If the EEPROM chip is welded on main PCB, replace the main PCB directly. Otherwise, check whether the EEPROM chip plugged in main PCB well?

  • No

    Correct the connection.

  • Yes

    Replace the indoor main PCB.

Power off, then turn on the unit 5 seconds later(reconnect the power wire).Is the error still displaying after several minutes?

• Yes

  Check all the wirings between indoor and outdoor, indoor main PCB and outdoor main PCB following the wiring diagram. Are all the wirings connected correctly?

  • Yes

    Measure Vs, is it moving alternately between positive value and negative value? (Vs is the voltage between S and N of outdoor unit.)

    • No

      Is the wiring to the indoor main PCB connected correctly?

      • Yes

        Change the indoor main PCB

        • Yes

          Power on. Is the error extinguished?

          • No

            Change the outdoor main PCB.

    • Yes

      Is the wiring to the outdoor main PCB connected correctly?

      • Yes

        Change the outdoor main PCB.

        • Yes

          Power on. Is the error extinguished?

          • No

            Change the indoor main PCB.

Check if the connections and power supply is normal?

• No

  Correct the connections. Turn on the unit when the power supply is good.

• Yes

  Indoor main PCB is defective. Replace indoor main PCB.

Shut off the power supply and turn it on 5 seconds later. Is it still displaying the error code?

• No

  The unit operates normally.

• Yes

  Shut off the power supply, rotate the fan by hand. Does it rotate properly?

  • No

    Find out the cause and have it solved. For example, check whether the fan is blocked or the bearing is broken?

  • Yes

    Check the wires of fan motor. Are all the connections good?

    • No

      Correct the connections

    • Yes

      Check whether the fan motor is normal through index 1?

      • No

        Replace the fan motor

        • Yes

          If the malfunction is still existing, replace the main PCB

      • Yes

        Check whether the main PCB is normal through index 2?

        • No

          Replace the main PCB. The malfunction is solved?

          • No

            Replace the fan motor

            • Yes

              If the malfunction is still existing, replace the main PCB

        • Yes

          Replace the fan motor

          • Yes

            If the malfunction is still existing, replace the main PCB

Check the connections between temperature sensor and PCB. Are the connections good?

• No

  Correct the connections.

• Yes

  Check the resistance value of the sensor via table1 and table 2, is it normal?

  • Yes

    Replace indoor or outdoor PCB.

  • No

    Replace the sensor and c h e c k i f t h e p r o b l e m happen again?

Shut off the power supply and turn it on 5 seconds later. Is it still displaying the error code?

• Yes

  Is there cool air blowing out from indoor air outlet?

  • Yes

    Check if T2 sensor is well fixed. Correct the installation or replace T2 sensor. Does the problem remain again?

    • Yes

      Replace indoor PCB.

  • No

    Is there any leakage? Especially the connection parts, such as the gas valve and the liquid valve.

    • Yes

      Repair the leakage and recharge the refrigerant.

    • No

      Is there any block ing ? (Such as the capillary or the welded points of the pipes.)

      • Yes

        Clear the blocking.

Check if the wiring between main PCB and compressor connected by error and if the wires and connectors are broken?

• Yes

  Correct the connection or replace the wires and connectors.

• No

  Check if the IPM installed correctly

  • No

    Correct the installation, tighten the screws and apply silicon grease.

  • Yes

    IPM continuity check. Check if the IPM terminal resistance values are uniform.

    • No

      Replace the IPM board or replace the main PCB if the IPM board and main PCB are integrated together.

    • Yes

      Check if the outdoor fan runs properly or the outdoor unit ventilation is good.

      • No

        Refer to the solution of fan speed has been out of control malfunction . Find out the cause and have it solved.

      • Yes

        Check if the compressor resistance values are uniform .

        • No

          Replace the compressor.

        • Yes

          Replace the outdoor main PCB if the main PCB and IPM are separate

Disconnect the unit with power supply and try to restart the unit when power supply gets normal.

Check if all the connections and wires are good?

• No

  Correct the connections or replace the wires.

• Yes

  Power on and when the unit is in standby, check if the voltage between P and N is around DC 310V or 340V or 380V? For different kinds of units, the voltage differs. Consult with technical engineer to get definite value. Then start up the unit, measure the voltage between P and N. Is it in 220V~400V?

  • No

    Replace the IPM board if it is separate with main PCB.

  • Yes

    Replace outdoor mainl PCB.

Check if the air flow system of indoor and outdoor units are obstructed?

• Yes

  Clear up the air inlet and outlet or the heat exchanger of indoor and outdoor units.

• No

  Turn off the power supply and turn it on 10 minutes later.

  • Yes

    Check if the unit can start normally

    • No

      Check if all the connection, especially the connection of OLP (Over Load Protector) sensor is good.

      • No

        Correct the connection.

      • Yes

        Measure the resistance between the two ports of the OLP. Is it zero?

        • No

          Replace the OLP.

        • Yes

          Replace the outdoor control PCB.

    • Yes

      Check if the refrigerant charge volume is normal?

      • Yes

        Refrigerant system is blocked, such as capillary or welded point of pipes.

      • No

        Recharge the correct refrigerant volume.

Check if the wiring between main PCB and compressor connected by error and if the wires and connectors are broken?

• Yes

  Correct the connection or replace the wires and connectors.

• No

  Check if the IPM installed correctly

  • No

    Correct the installation, tighten the screws and apply silicon grease.

  • Yes

    IPM continuity check. Check if the IPM terminal resistance values are uniform

    • No

      Replace the IPM board or replace the main PCB if the IPM board and main PCB are integrated together.

    • Yes

      Check if the outdoor fan runs properly or the outdoor unit ventilation is good.

      • No

        Refer to the solution of fan speed has been out of control malfunction . Find out the cause and have it solved.

      • Yes

        Check if the compressor resistance values are uniform .

        • No

          Replace the compressor

        • Yes

          Replace the outdoor main PCB if the main PCB and IPM are separate.