LG Heat Pump Error Code E279

E279 indicates an OPEN or SHORT circuit fault with the outdoor suction temperature sensor on your LG heat pump. The suction temperature sensor monitors refrigerant temperature at the outdoor unit and feeds that data to the control board. When the board cannot read a valid signal from this sensor, it stops normal operation and displays E279 to prevent the system from running with inaccurate data.

You should not continue operating the heat pump with E279 active. The suction temperature sensor provides data the system needs to protect the compressor and manage refrigerant flow correctly. Running the unit without a valid sensor signal could result in compressor damage or other component failures over time.

Repair costs vary depending on the root cause. If only a reconnection is needed, there may be minimal cost beyond a service call fee, which typically ranges from around 75 to 150 dollars. Replacing the suction temperature sensor itself is generally an affordable repair, with parts and labor usually falling in the range of 100 to 300 dollars. If the outdoor PCB needs replacement, costs can be significantly higher, often between 300 and 700 dollars or more depending on the model.

Some causes of E279, such as a disconnected connector at the outdoor PCB, can be addressed by a knowledgeable homeowner comfortable working around electrical components. However, diagnosing a failed sensor requires a multimeter and familiarity with NTC sensor resistance testing. If the sensor or wiring needs replacement, or if the control board is suspected, a qualified HVAC technician should handle the repair.

A power reset may temporarily clear the error display, but E279 will return if the underlying sensor fault has not been corrected. The control board will re-detect the open or short circuit condition as soon as it checks the sensor input again. A reset is useful for confirming whether the fault is intermittent, but it is not a fix for a failed sensor or damaged wiring.