Samsung Air Conditioner Error Code E304

E304 indicates that the COND-OUT SUB 1 temperature sensor at the condenser outlet has triggered an OPEN or SHORT fault. This means the control board is detecting that the sensor circuit has either lost continuity or has shorted out, producing an invalid temperature reading. The system shuts down to prevent potential damage to the compressor or refrigerant circuit.

No. When E304 is active, the system has typically shut itself down as a protective measure because it cannot monitor condenser outlet temperature accurately. Attempting to bypass or ignore this fault and force the unit to run risks compressor damage or refrigerant system issues. The fault should be diagnosed and repaired before resuming normal operation.

Repair costs depend on what component has failed. A replacement thermistor sensor typically costs in the range of $20 to $80 for the part, while a control board can range from $100 to $300 or more. Adding labor charges for a qualified HVAC technician, total repair costs commonly fall between $100 and $500 depending on the diagnosis, the specific model, and local labor rates.

A knowledgeable DIYer can inspect the sensor connector and wiring harness for visible corrosion or damage, and can test the thermistor resistance with a multimeter. However, if the sensor itself needs replacement or the fault is traced to the control board, working on the outdoor condenser unit involves handling electrical components that may carry line voltage, so hiring a certified technician is strongly recommended for those repairs.

A power reset may temporarily clear the error code, but if the underlying sensor or wiring fault is still present, the E304 code will return once the system restarts and begins reading from the sensor again. A reset is only a valid fix if the fault was caused by a one-time transient condition, which is rare for this error type.