Samsung Heat Pump Error Code E104

E104 means the compressor has been shut down by the low pressure protection control. The system detected refrigerant pressure on the low side below 2.6 kg/cm2 during cooling or below 1.4 kg/cm2 during heating. This is a safety function designed to prevent compressor damage from operating with insufficient refrigerant pressure.

No. The E104 protection control shuts the compressor down specifically to prevent mechanical damage from low-pressure operation. Attempting to reset the unit and continue running it without correcting the root cause risks compressor failure, which is a costly repair. The system should remain off until a technician has identified and resolved the underlying issue.

A power reset may temporarily clear the fault and allow the unit to restart, but if the underlying cause has not been corrected, the low pressure protection will trigger again and E104 will return. Resetting without diagnosis is not a repair and can risk further damage to the compressor if the system is repeatedly restarted under low-pressure conditions.

Some causes, such as a partially closed service valve or a dirty coil, can be addressed without specialized equipment. However, diagnosing refrigerant charge, sensor accuracy, or expansion valve issues requires a manifold gauge set and the S-net diagnostic tool, along with EPA certification to handle refrigerants. Most homeowners should contact a licensed HVAC technician for a full diagnosis.

Repair costs vary widely depending on the cause. Cleaning coils or opening a service valve involves only a service call fee, typically in the range of $75 to $150. If a refrigerant leak is involved, leak repair plus recharge can range from $200 to $600 or more depending on the refrigerant type and leak location. Compressor replacement, if damage has already occurred, can range from $800 to $2,500 or higher including labor.