LG Heat Pump Error Code E308

E308 indicates an open or short circuit fault detected in the discharge temperature sensor for fixed capacity compressor 1. This sensor measures refrigerant temperature at the compressor outlet and is essential for safe compressor operation. LG's control system only triggers this fault when outdoor temperatures are above -10°C. The unit will disable the affected compressor until the sensor circuit is restored to a valid reading.

The system automatically disables fixed capacity compressor 1 when E308 is active, which is a protective response to prevent compressor damage from unmonitored discharge temperatures. Continuing to attempt to run the unit without resolving the fault is not recommended, as repeated fault cycling can stress other components. Have the sensor and wiring inspected before resuming normal operation.

A power cycle or reset may temporarily clear the fault display, but E308 will return as soon as the control board runs its sensor check again and detects the open or short circuit condition. Resetting does not repair a failed sensor, broken wire, or loose connector. The underlying wiring and sensor issue must be corrected for the error to clear permanently.

Some basic checks are within reach of a knowledgeable DIYer, such as inspecting the sensor connector at the outdoor PCB and confirming it is fully seated. However, measuring sensor resistance accurately and diagnosing wiring faults in the outdoor unit typically requires a multimeter and familiarity with refrigeration electrical systems. Replacing the sensor or PCB involves working inside the outdoor unit and should be performed by a qualified technician.

Repair costs vary depending on what has failed. A connector reseating or minor wiring repair during a service visit typically runs in the range of $75 to $150 for the diagnostic and labor. If the discharge temperature sensor itself needs replacement, parts and labor combined generally fall in the range of $150 to $350. PCB replacement is significantly more expensive, often ranging from $400 to $800 or more depending on the model.