Samsung Heat Pump Error Code E304

E304 is a CT over-current error, meaning the current transformer sensor detected that the compressor was drawing more than 20 amperes for at least 5 continuous seconds. The system shuts down the compressor automatically to prevent damage. The fault can originate from a genuine compressor problem or from a defective CT sensor reporting incorrect values.

No. The E304 code indicates the system has already shut the compressor down as a protective measure. Attempting to force the unit to run without resolving the underlying cause risks permanent compressor damage and potential electrical hazards. Leave the unit off until a technician can diagnose the fault.

Repair costs depend heavily on the root cause. Replacing a faulty CT sensor is relatively inexpensive, typically in the range of a few parts and a service call fee. A compressor replacement is significantly more expensive, often ranging from several hundred to over a thousand dollars depending on the unit size and labor rates in your area. Refrigerant recharge costs vary by refrigerant type and the amount needed.

Some basic checks are accessible to a knowledgeable DIYer, such as inspecting the CT sensor connector for visible corrosion or loose seating. However, diagnosing compressor current draw, measuring winding resistance, and checking refrigerant pressures require specialized tools and training. A licensed HVAC technician should handle the full diagnosis and any refrigerant-related work.

A power reset may temporarily clear the code and allow the unit to restart, but if the root cause is not corrected, the error will return once the compressor again exceeds 20A for more than 5 seconds. Repeated resets without repair can worsen compressor damage if the over-current condition is genuine.