The HP will display an error code if it is unable to function normally.
Error codes are indicated by a red LED on the control panel. The control panel is visible via a small window at the right side of the heat pump and it can be accessed by removing the heat pump top cover (4 screws).

After a component is replaced or the inspection is completed, cycle power to the unit several times to confirm the error does not re-occur.
Below is the list of the error codes. If the corrective action does not solve the error problem, a malfunction of the PCB valve is highly likely.
Error code | Reason for the error | Corrective action |
H9 | HP ambient(outdoor) temperature thermistor error | Check the thermistor connectors on the main PCB or control PCB in the heat pump unit for any disconnection, fall-off, wire breakage or short circuit. Measure resistance of the thermistor indicated by the error code.
|
HC | HPwater outlet (outgoing) temperature thermistor error |
J3 | HP discharge temperature thermistor error |
J5 | HP suctiontemperature thermistor error |
J6 | HP defrosttemperature thermistor error |
J8 | HPwater inlet (return) temperature thermistor error |
H7 | Tank temperature thermistor error | - Check the thermistor cable on the terminal block in the heat pump unit for any disconnection, fall-off, wire breakage or short circuit.
- Measure resistance of the thermistor indicated by the error code.
|
E6 | Compressor bootingerror | - Check the compressor connector.
- Replace the main PCB or heat pump.
|
H6 | Compressor revolution error | - Check the supply voltage.
- Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
|
Error code | Reason for the error | Corrective action |
| | |
U0 | Refrigerant leakageerror | - Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
E1 | Main PCB error | |
E2 L7 | Control PCB error | |
F5 | Communication error between main PCB to control PCB | - Check the communication connector on the main PCB and control PCB.
- Replace the main PCB or control PCB.
|
E8 | High inlet current error | - Check the installation location.
- Check the supply voltage.
- Replace the main PCB or heat pump.
|
H8 | Current error | |
L4 | High temperature of module error | - Check the installation location.
- Remove foreign objects from the evaporator coil (e.g. fallen leaves, grass, snow).
- Check the fan motor is not flowing by dirt.
- Replace the main PCB or fan motor.
|
L5 | High outlet current error | - Measure resistance of the discharged thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
P4 | Module temperature thermistor error | |
U2 | High voltage error | |
HJ | Water circuit error | - Check the inlet water valve.
- Check for any piping bend, blockage, kink or frozen.
- Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
EC | High water outlet error | - Check the water circuit is not flowing by air, dirt or scaling.
- If the water circulation pump is not working, replace the pump.
- Measure resistance of water outlet (outgoing) thermistor.
- Replace the main PCB.
|
E9 | Water circulation pump error | - Check the water is full in the tank.
- If the water circulation pump is not working, replace the pump.
- Check the revolution of pump by controller. If the revolution is low, replace the pump.
- Replace the main PCB.
|
Error code | Reason for the error | Corrective action |
E7 | Fan motor locked | - Remove foreign objects around the fan motor.
- Check the fan motor connectors on the main PCB.
- Replace the main PCB.
|
F3 | Discharged temperature error | - Measure resistance of the discharged thermistor.
- Replace the main PCB or heat pump.
|
Error code | Reason for the error | Corrective action |
H9 | HP ambient(outdoor) temperature thermistor error | Check the thermistor connectors on the main PCB or control PCB in the heat pump unit for any disconnection, fall-off, wire breakage or short circuit. Measure resistance of the thermistor indicated by the error code.
|
HC | HPwater outlet (outgoing) temperature thermistor error |
J3 | HP discharge temperature thermistor error |
J5 | HP suctiontemperature thermistor error |
J6 | HP defrosttemperature thermistor error |
J8 | HPwater inlet (return) temperature thermistor error |
H7 | Tank temperature thermistor error | - Check the thermistor cable on the terminal block in the heat pump unit for any disconnection, fall-off, wire breakage or short circuit.
- Measure resistance of the thermistor indicated by the error code.
|
E6 | Compressor bootingerror | - Check the compressor connector.
- Replace the main PCB or heat pump.
|
H6 | Compressor revolution error | - Check the supply voltage.
- Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
|
Error code | Reason for the error | Corrective action |
| | |
U0 | Refrigerant leakageerror | - Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
E1 | Main PCB error | |
E2 L7 | Control PCB error | |
F5 | Communication error between main PCB to control PCB | - Check the communication connector on the main PCB and control PCB.
- Replace the main PCB or control PCB.
|
E8 | High inlet current error | - Check the installation location.
- Check the supply voltage.
- Replace the main PCB or heat pump.
|
H8 | Current error | |
L4 | High temperature of module error | - Check the installation location.
- Remove foreign objects from the evaporator coil (e.g. fallen leaves, grass, snow).
- Check the fan motor is not flowing by dirt.
- Replace the main PCB or fan motor.
|
L5 | High outlet current error | - Measure resistance of the discharged thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
P4 | Module temperature thermistor error | |
U2 | High voltage error | |
HJ | Water circuit error | - Check the inlet water valve.
- Check for any piping bend, blockage, kink or frozen.
- Measure resistance of each thermistor.
- Measure resistance of coil of expansion valve to check open or short circuit.
- Replace the main PCB or heat pump.
|
EC | High water outlet error | - Check the water circuit is not flowing by air, dirt or scaling.
- If the water circulation pump is not working, replace the pump.
- Measure resistance of water outlet (outgoing) thermistor.
- Replace the main PCB.
|
E9 | Water circulation pump error | - Check the water is full in the tank.
- If the water circulation pump is not working, replace the pump.
- Check the revolution of pump by controller. If the revolution is low, replace the pump.
- Replace the main PCB.
|
Error code | Reason for the error | Corrective action |
E7 | Fan motor locked | - Remove foreign objects around the fan motor.
- Check the fan motor connectors on the main PCB.
- Replace the main PCB.
|
F3 | Discharged temperature error | - Measure resistance of the discharged thermistor.
- Replace the main PCB or heat pump.
|