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Error code reference

LG Hvac Error Code 44

PCB sees ODU air sensor as open or shorted.

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PCB sees ODU air sensor as open or shorted.

First step from the service manual

Must be 5,600Ω at 38°C/100°F & 20,700Ω at 10°C/50°F. Ohm thermistor in water, measure water temperature; with perfect thermistor & plug connection, change PCB. PTAC LPxxxC: check DIP switch settings.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 44 means on a LG hvac

Error code 44 on an LG HVAC unit indicates that the main PCB (printed circuit board) has detected an open or shorted condition on the outdoor unit (ODU) air temperature thermistor circuit. This thermistor is a negative temperature coefficient (NTC) sensor that the PCB uses to monitor ambient air temperature at the outdoor unit. The board continuously checks the resistance value coming from this sensor, and when the reading falls outside the expected range, it flags the fault and locks out normal operation to prevent potential equipment damage.

The thermistor should measure approximately 5,600 ohms at 38 degrees Celsius (100 degrees Fahrenheit) and approximately 20,700 ohms at 10 degrees Celsius (50 degrees Fahrenheit). An open circuit will drive resistance toward infinity, while a shorted circuit will collapse resistance toward zero. Both conditions are easily confirmed by disconnecting the sensor and measuring resistance with a multimeter, ideally by submerging the sensor tip in water at a known temperature to get an accurate reference reading.

For PTAC models in the LPxxxC series, DIP switch configuration should be verified before condemning any components, as incorrect switch settings can produce this error. If the thermistor resistance values check out correctly and all wiring connections at the sensor plug are secure and clean, the PCB itself is the likely source of the fault and will need to be replaced.

Source: manufacturer service documentation.

Common causes of 44

  1. 01

    Failed ODU air thermistor

    Part replacement

    The outdoor air temperature sensor has failed internally, causing its resistance to read as open or shorted. Confirm by measuring resistance at the known reference values: 5,600 ohms at 38C/100F and 20,700 ohms at 10C/50F.

  2. 02

    Loose or corroded thermistor connector

    Wiring / connection

    The wiring plug connecting the thermistor to the PCB may be loose, corroded, or making intermittent contact, causing the board to see an open circuit. Inspect the connector for moisture damage, corrosion, or bent pins and reseat it firmly.

  3. 03

    Damaged thermistor wiring

    Wiring / connection

    The wiring harness between the outdoor air sensor and the PCB may be chafed, pinched, or broken, creating an open or short in the circuit. Visually trace the wire run for any visible damage and check continuity end to end.

  4. 04

    Incorrect DIP switch settings (LPxxxC PTAC models)

    Wiring / connection

    On LG PTAC units in the LPxxxC series, incorrect DIP switch configuration on the PCB can trigger error code 44 even when the sensor itself is functional. Verify that all DIP switches are set according to the unit specifications before replacing any components.

  5. 05

    Faulty PCB

    Part replacement

    If the thermistor resistance values are correct at the reference temperatures and all wiring and connections are confirmed good, the PCB has likely failed internally and is misreading the sensor signal. Board replacement is required in this scenario.

See the test procedure for each cause

Frequently asked questions about 44

What does 44 mean on a LG hvac?
Error code 44 means the main control board (PCB) is detecting an open or shorted signal from the outdoor unit air temperature sensor (thermistor). The board expects a specific resistance range from this sensor and has determined the reading is out of range. The unit will not operate normally until the fault is resolved. This can be caused by a failed sensor, damaged wiring, a loose connector, or in some cases a faulty PCB.
How do I fix error code 44 on my LG HVAC?
Start by disconnecting the outdoor air thermistor and measuring its resistance with a multimeter, comparing it against the reference values of 5,600 ohms at 38C/100F and 20,700 ohms at 10C/50F. If values are incorrect, replace the thermistor. If resistance is correct, inspect the wiring and connector for damage or corrosion. On LPxxxC PTAC models, also verify the DIP switch settings before replacing parts. If wiring and sensor both test good, the PCB will need to be replaced.
Will resetting my LG HVAC clear error code 44?
A power reset may temporarily clear the fault display, but the error will return if the underlying problem with the outdoor air thermistor or its wiring is not corrected. Because the PCB actively monitors the sensor signal during operation, any open or short condition will trigger the code again shortly after restart. A reset alone is not a repair and should not be relied upon.
Is it safe to run my LG HVAC while error code 44 is active?
Error code 44 causes the unit to stop normal operation because it cannot accurately read outdoor air temperature. Attempting to force operation without a valid sensor reading could result in improper system behavior and potential equipment damage. It is best to leave the unit off and address the fault before resuming use.
How much does it cost to repair error code 44 on a LG HVAC?
Repair costs vary depending on the cause. If only the outdoor air thermistor needs replacement, parts and labor typically range from around 80 to 200 dollars. If the PCB is the failed component, costs are generally higher, often ranging from 200 to 600 dollars or more depending on the model and labor rates in your area. Getting a diagnostic assessment from a qualified technician before purchasing parts is advisable.

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