Error code
tC9
Meaning
The compressor temperature sensor detected a problem
Moderate
What to do
Why this happens
Causes may include an out-of-range compressor IPM temperature sensor, a wiring fault in its circuit, or an Inverter PBA fault impacting the sensor reading.
How to fix it
This one needs a professional technician — it involves the heat pump system.
SourceSamsung service manual / Customer Repair Guide