List of error codes for the LG Therma V air-to-water heat pump

List of error codes for the air-to-water heat pump – LG Therma V

Download the manual for the LG THERMA V air-to-water heat pump

Turn off the power supply before starting any troubleshooting

Troubleshooting: issues during operation

N°	Problem	Reason	Solution
1	Heating or cooling is not satisfactory.	1. Incorrect target temperature setting.	00 Set the target temperature correctly. 01 Check whether the temperature is based on water or air. Refer to function codes 03 and 05 in chapter 6.
		30 Insufficient water charge.	65 Check the pressure gauge and add water until it reads between 200 and 250 kPa.
		30 Low water flow.	65 Check whether the strainer has collected too many particles. If so, it must be cleaned. 66 Make sure the internal water pump speed is NOT set to “High.” It should be set to “High.” 67 Make sure the pressure gauge reads above 30 kPa. 68 Check whether the water line is clogged due to a buildup of particles or limescale.
2	Even though the power supply is correct (the remote control shows information), the unit does not start.	00 Inlet water temperature too high.	67 If the inlet water temperature is above 55°C, the unit will not operate in order to protect the system.
2		79 Inlet water temperature too low.	30 If the inlet water temperature is below 5°C, the unit will not operate in order to protect the system. Wait for the unit to raise the inlet water temperature.
3	Water pump noise.	65 Air purge not completed.	30 Open the air purge valve cap and add water until the pressure gauge reads between 200 and 250 kPa. 31 If water does not spurt out when you press the nozzle (at the top of the hole), the air purge is not complete. Once purging is complete, water will spurt out like a fountain.
3	Water pump noise.	65 Low water pressure.	30 Make sure the pressure gauge reads above 30 kPa. 31 Check the operation of the expansion tank and the pressure gauge.
4	Noise generated by the water pump.	66 Too much water charged.	• Drain water by opening the safety valve switch until the pressure gauge reads between 200 and 250 kPa.
4	Noise generated by the water pump.	• Expansion tank damaged.	• Replace the expansion tank.
5	The domestic hot water is not hot.	• Thermal protector of the water tank heater activated.	• Open the side panel of the domestic hot water tank and press the thermal protector reset button (for more information, refer to the domestic hot water tank’s installation manual).
5	The domestic hot water is not hot.	• Domestic hot water heating is disabled.	• Press the button and check whether the icon appears on the remote control.

Inspection, maintenance, and troubleshooting points

Troubleshooting: error code

No. of code	Description	Cause	Normal conditions
1	Issue with the remote ambient air sensor	• Incorrect connection between the sensor and the main PCB (thermal element). • Fault in the main PCB (thermal element) • Faulty sensor	• Resistance: 10 kΩ at 25°C (unplugged) → for the remote ambient air sensor • Resistance: 5 kΩ at 25°C (unplugged) → for all sensors EXCEPT the remote ambient air sensor • Voltage: 2.5 V DC at 25°C (plugged in) (for all sensors) • Refer to the resistance/temperature table to check the different values
2	Issue with the refrigerant sensor (inlet side)
6	Issue with the refrigerant sensor (outlet side)
8	Issue with the water tank sensor
16	Issue with the sensors
17	Issue with the inlet water sensor
18	Issue with the outlet water sensor
19	Issue with the intermediate water sensor
3	Poor communication between the wired remote control and the indoor unit	• Incorrect connection between the sensor and the main PCB (thermal element) • Fault in the main PCB (thermal element) • Faulty sensor	• The connecting cable between the remote control and the main PCB assembly (thermal element) must be firmly secured. • The output voltage from the PCB must be 12 V DC.
5	Poor communication between the unit’s main PCB assembly (thermal element) and the main PCB assembly (inverter)	• The transmission connector is not plugged in • The connecting wires are improperly connected • The communication line is damaged • Abnormal main PCB assembly (inverter) • Abnormal main PCB assembly (thermal element)	• The connecting cable between the remote control panel and the main PCB assembly (thermal element) must be firmly secured.
53
9	PCB program error (EEPROM)	• The EEPROM has electrical or mechanical damage.	• This error cannot be tolerated
14	Issue with the flow switch	• The flow switch is open while the internal water pump is running • The flow switch is closed while the internal water pump is not running • The flow switch is open while DIP switch No. 5 on the main PCB (thermal element) is on.	• The flow switch must be closed when the internal water pump is running or when DIP switch No. 5 on the main PCB (thermal element) is on. • The flow switch must be open when the internal water pump is not running
15	Overheated water pipe	• Abnormal operation of the electric heater • The outlet water temperature is above 57°C	• If no issue is found with the electric heater control device, the maximum outlet water temperature is 57°C.
20	The fuse is damaged	• The fuse has blown due to abnormal overheating of the internal electric heater • The fuse has a mechanical fault • The wire is damaged	• This error will not appear if the electric heater tank temperature is below 80°C.