LG DLEX3700 Series Owner's Manual page 31

Restricted or Blocked Airflow
Avoid long runs or runs with multiple elbows or
bends.
Excess or crushed
transition duct
Check for blockages and lint buildup.
Lint buildup or blockage
Make sure the ductwork is not crushed or restricted.
Too many elbows or
exhaust too long
Crushed or damaged
exhaust
INSTALLATION 31