Error code
Ct
Meaning
Your dryer detected restricted airflow during a vent test
Moderate
What to do
Why this happens
Causes may include extreme ambient temperatures affecting vent test accuracy, recent operation leaving the dryer hot inside, or a thermistor issue leading to incorrect temperature readings.
How to fix it
Clean the entire exhaust vent from the dryer to the outside. If the vent run is very long, consider having it professionally cleaned or shortened.
SourceSamsung service manual / Customer Repair Guide