LG
The LG THERMA V R32 Hydrosplit is a 16 kilowatt air-to-water heat pump with a 4.6 SCOP and 65 degree maximum flow temperature, designed for high-efficiency domestic heating.
The LG THERMA V AIR-TO-WATER HEAT PUMP is a high-capacity R32 Hydrosplit system designed for domestic heating and hot water. Available in 12kW, 14kW, and 16kW variants, this DC inverter-driven split unit provides flow temperatures up to 65°C. This technical reference covers the R32 Hydrosplit series, including the ZHBW126B0 and ZHBW168B0 models, providing engineers with essential installation data, performance specifications, and a comprehensive diagnostic fault code directory for troubleshooting and maintenance.
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Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.
The LG THERMA V R32 Hydrosplit is a split-type air-source heat pump system utilizing R32 refrigerant. Unlike traditional split systems, the Hydrosplit connects the indoor and outdoor units via water pipes, eliminating the need for refrigerant handling inside the property. The range includes single-phase (220-240V) and three-phase (380-415V) models, with the ZHBW166B0 delivering a nominal capacity of 16kW.
Efficiency is a core characteristic of the Therma V range. At A7W35 conditions, the system achieves a COP of 4.8, while the seasonal coefficient of performance (SCOP) is rated at 4.6 for 35°C applications and 3.5 for 55°C applications. This performance allows for a maximum flow temperature of 65°C, making it suitable for both new builds and retrofit projects where existing radiator sizing may require higher temperatures. The outdoor unit, housed in a U3 chassis, measures 1380mm in height, 950mm in width, and 330mm in depth, with a net weight of 91.7kg. It operates with a sound power level of 61 dB(A), which can be reduced to 60 dB(A) when quiet mode is active.
Hydraulic requirements include a minimum water flow rate of 15 litres per minute and a maximum operating pressure of 3 bar. The indoor unit (ZHNW16B0) is compact, measuring 850mm by 490mm by 315mm, and integrates the primary control electronics. For control, the system supports Modbus communication and is Smart Grid ready, allowing for integration with various LG accessories such as the PREMTW101 remote controller or the PWFMDD200 Wi-Fi module.
Maintenance and diagnostics are facilitated through the onboard PCB. The system monitors various parameters, including flow rates and sensor resistances. Common issues, such as fault code 14, indicate low flow detection, often caused by strainer blockages or pump malfunctions. Code 21 signifies a DC Peak or IPM fault, requiring inspection of the inverter compressor and outdoor fan. Engineers must perform annual heat exchanger cleaning to remove debris and ensure optimal heat transfer. The R32 refrigerant charge is factory-set at 2.1kg, and F-Gas certification is required for any work involving the refrigerant circuit in the outdoor unit.
Every fault code listed in the manufacturer brochure, with likely causes and engineer actions. Each code has a permalink — paste a URL like https://www.boilertag.com/heat-pumps/lg/hu161mrb-u30#fault-01 to jump straight to the entry.
| Code | Meaning | Details |
|---|---|---|
| 01 | Problem in Remote Room Air sensor Show causes & actionsRemote air temperature sensor of MainPCB(indoor) is open or short. Likely causes
Engineer action Re-attach the sensor to the main PCB. Place the thermistor in the correct position. Replace the sensor. Replace the Main PCB(Indoor) | Details |
| 02 | Problem in Refrigerant (Inlet side) sensor Show causes & actionsRefrigerant inlet pipe temperature sensor of indoor unit is open or short. Likely causes
Engineer action Check sensor connection. Check sensor resistance. Replace sensor if defective. | Details |
| 03Lockout | Communication error between indoor unit and wired remote controller Show causes & actionsCommunication between wired remote controller and indoor unit is not possible. Likely causes
Engineer action Check if the wired remote control connector and terminal block are properly connected. Check if the specifications of the wired remote controller cable are recommended (AWG 24, 3 or higher). Check if the communication line is normal without short circuit or disconnection. Inspect Main PCB and replace. Inspect Wired remote controller and replace. | Details |
| 05 | Communication error between Main PCB(Indoor) and Main PCB(Outdoor Cycle) Show causes & actionsThere is no communication between the Main PCB(Indoor) and the Main PCB(Outdoor cycle). Likely causes
Engineer action Check input power and GND connection. Check wiring of the harness connected to the PCB. Check for products or wires that can cause noise. Check for visible defects on Indoor PCB (Noise filter, Capacitor etc.). | Details |
| 09Lockout | PCB Program (EEPROM) Fault Show causes & actionsA defect occurred in the optional EEPROM connected to the Main PCB(Indoor). Likely causes
Engineer action Check if the Option PCB is correctly plugged into Main PCB(Indoor). Check if the EEPROM is in a normal state (dents, burn marks). Check if the EEPROM insertion direction is correct (groove direction). Replace the EEPROM or Main PCB(Indoor). | Details |
| 14Lockout | Problem in Flow rate Show causes & actionsLow flow detection during pump operation. Likely causes
Engineer action Check Water pipe leakage & low flow rate. Check strainer blockage and clean. Check PCB Connector Connection: CN_F_SENSOR. Check Circulating Pump Operation. Check PCB Pump Signal Output Voltage. Check and Change the flow sensor. | Details |
| 15Lockout | Water pipe strange overheat Show causes & actionsWhen the temperature of the water pipe exceeds 72 °C. Likely causes
Engineer action Inspect Facility. Check if the water pipe sensor is inserted in place. Check if the water piping sensor is normal. Replace the Main PCB(Indoor). | Details |
| 16Lockout | Problems in sensors Show causes & actionsHeater water temperature sensor error, Temperature sensor error, Water temperature sensor error occurring at the same time. Likely causes
Engineer action Check if the sensor is properly inserted into the pipe. Check if the measured resistance value matches the table. Check if the measured voltage value matches the table. Replace the Main PCB(Indoor). | Details |
| 20Lockout | Electric heater overheated Show causes & actionsFuse of electric heater is blown due to overheat. Likely causes
Engineer action Check if the harness is properly connected on PCB (CN-SOLAR). Remove CN-Solar connector and check open/short with a tester. Replace Thermo switch or Electric heater. Reset procedure 1Ø Model: Manually reset by pressing the button on the thermo switch. 3Ø Model: After checking that the temperature is below 70 °C, reconnect the power (automatic reset). | Details |
| 21 | DC PEAK (IPM Fault) Show causes & actionsIPM of inverter drive is abnormal or Inverter comp. is self-defective. Likely causes
Engineer action Check if the fan is locked. Check the shield around the heat exchanger. Check refrigerant pressure. Check compressor resistance (0.529 ~ 0.631 Ω). Check insulation resistance (50 MΩ). Replace Inv PCB(Outdoor). | Details |
| 232Lockout | Problem in Flow Sensor Show causes & actionsFlow Sensor of indoor unit is damaged. Likely causes
Engineer action Check sensor connection. Check sensor voltage (0.5 ~ 3.5 V). Replace sensor if defective. | Details |
| 52Lockout | Communication Error Inv PCB(Outdoor) <-> Main PCB(Outdoor Cycle) Show causes & actionsIt is failed to receive wired Inv PCB(Outdoor) signal in Main PCB(Outdoor Cycle). Likely causes
Engineer action Check connection status. Check communication LED (yellow) blinking normally. Replace Inv PCB(Outdoor) or Inverter board. | Details |
Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.
Engineer: Check if the wired remote control connector and terminal block are properly connected. Check if the specifications of the wired remote controller cable are recommended (AWG 24, 3 or higher). Check if the communication line is normal without short circuit or disconnection. Inspect Main PCB and replace. Inspect Wired remote controller and replace.
Triggered by fault code 03.
Engineer: Check if the Option PCB is correctly plugged into Main PCB(Indoor). Check if the EEPROM is in a normal state (dents, burn marks). Check if the EEPROM insertion direction is correct (groove direction). Replace the EEPROM or Main PCB(Indoor).
Triggered by fault code 09.
Engineer: Check Water pipe leakage & low flow rate. Check strainer blockage and clean. Check PCB Connector Connection: CN_F_SENSOR. Check Circulating Pump Operation. Check PCB Pump Signal Output Voltage. Check and Change the flow sensor.
Common questions from engineers and homeowners about the LG HU161MRB U30.
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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 30 April 2026.
Triggered by fault code 14.
Engineer: Inspect Facility. Check if the water pipe sensor is inserted in place. Check if the water piping sensor is normal. Replace the Main PCB(Indoor).
Triggered by fault code 15.
Engineer: Check if the sensor is properly inserted into the pipe. Check if the measured resistance value matches the table. Check if the measured voltage value matches the table. Replace the Main PCB(Indoor).
Triggered by fault code 16.