Error code
C9/C90
Meaning
Your dryer vent is over 90% blocked — needs immediate cleaning
Critical
What to do
Why this happens
Causes may include severe lint buildup in ducts, blockage in the exhaust or hood, and damage such as crushing or kinking of the duct.
How to fix it
Do not use the dryer until the vent is cleaned. Clean the entire exhaust vent from the dryer to the outside wall. For this level of blockage, consider hiring a professional vent cleaning service.
SourceSamsung service manual / Customer Repair Guide