Samsung Air Conditioner Error Code YEL_ON_GRN_ON

YEL_ON_GRN_ON indicates a heatsink temperature trip in the outdoor unit. The heatsink is a metal component that cools the inverter power module controlling the compressor. When this heatsink gets too hot, the system shuts down automatically to protect the electronics from permanent damage. The yellow and green LED indicators on the outdoor unit control board illuminate together to signal this specific fault condition.

The error itself represents a safety protection feature, not an immediate hazard. The system shuts down to prevent damage to the inverter power module, which could otherwise fail in a more serious way if overheating continued. You should not attempt to defeat or bypass this protection. Leave the unit off and diagnose the root cause before restarting.

Repair costs vary significantly depending on the root cause. Cleaning and airflow corrections may cost little to nothing beyond a service call fee, which typically ranges from $75 to $150. Fan motor replacement generally falls in the $200 to $450 range including parts and labor. Control board or IPM repairs can range from $300 to $700 or more depending on parts availability and the extent of the damage.

Some causes of this error are accessible to knowledgeable DIYers. Clearing debris from around the outdoor unit, cleaning clogged heatsink fins, and verifying that the outdoor fan is spinning are reasonable first steps. However, diagnosing and repairing the fan motor drive circuit, replacing the fan motor, or servicing the IPM board involves working with high-voltage components and should be performed by a qualified technician.

A power reset may temporarily clear the fault and allow the unit to restart, but the error will return if the underlying cause is not resolved. If the heatsink or airflow issue persists, the unit will trip again, often faster on subsequent attempts as residual heat remains. A reset without diagnosis and repair is not a lasting solution.