LG Air Conditioner Error Code 134

Error code 134 indicates that the discharge temperature sensor on compressor 2 of the Sub2 outdoor unit is reading an open or short circuit condition. This applies to 3-unit outdoor configurations. The system uses this sensor to monitor compressor outlet temperatures, and when the signal falls outside acceptable parameters, the system triggers this fault to protect the compressor from damage.

No. The system has flagged this error because it cannot verify safe discharge temperatures on compressor 2. Continuing to operate the system without a functioning discharge temperature sensor risks compressor overheating and potentially permanent compressor damage. The unit should remain off until the sensor fault is diagnosed and repaired.

A power reset may temporarily clear the error code, but if the underlying sensor fault is still present, the code will return once the system attempts to operate and reads the out-of-range signal again. Resetting without addressing the root cause does not fix the problem and can delay necessary repairs. The fault condition should be diagnosed and corrected before returning the system to normal operation.

A knowledgeable DIYer can start by checking that the sensor connector is fully seated and free of visible damage or corrosion. However, testing thermistor resistance values, tracing wiring faults in a multi-unit outdoor system, and replacing PCB components requires technical skill and proper tools. Because this involves a commercial-style multi-unit system, professional service is strongly recommended if basic connection checks do not resolve the fault.

If the fix is a simple connector reseating, there may be little to no parts cost, though a service call fee will still apply. A replacement discharge temperature thermistor typically falls in the range of $15 to $60 in parts. If the outdoor unit PCB requires replacement, costs can range from $200 to $600 or more depending on the unit model. Labor costs will vary by region and service provider.