LG Heat Pump Error Code E322

E322 indicates a fault with the SUMP TEMP FIXED 1 sensor on the outdoor unit. The PCB has detected that the sensor signal voltage is either above 4.95V or below 0.5V, corresponding to temperatures outside the range of -30°C to 151°C. This is interpreted as an open or short circuit condition in the sensor or its wiring. The fault is only triggered when outdoor ambient temperature is above -10°C.

No. The sump temperature sensor protects the compressor from operating under unsafe thermal conditions. Running the system while this sensor fault is active risks compressor damage, which is a costly repair. The unit will typically shut itself down when this code is active, and that shutdown should be respected until the fault is resolved.

Repair costs depend on the root cause. If the fix is simply reseating a disconnected connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing the sump temperature sensor itself usually adds $50 to $150 in parts. If the outdoor unit PCB requires replacement, costs can range from $300 to $700 or more depending on the model and labor rates in your area.

A knowledgeable DIYer can start by checking whether the sensor connector has come loose from the outdoor unit PCB and reseating it. You can also measure resistance across the sensor terminals to determine if the sensor itself has failed. However, if the sensor or wiring needs replacement, working inside the outdoor unit requires comfort with electrical components and safe power isolation procedures. When in doubt, contact a qualified technician.

A reset may temporarily clear the error code, but if the underlying sensor fault is still present, E322 will return once the unit restarts and the PCB re-checks the sensor signal. A reset is useful for confirming whether the fault is intermittent, such as a loose connector, but it does not repair a failed sensor or damaged wiring.