Start with airflow
A dryer dries with a stream of warm air that has to leave the house through the vent. When lint builds up in the duct, the moist air stays in the drum. Clothes come out warm and damp, the top of the dryer gets hot, and the thermal fuse can blow.
7 common causes
- Clogged vent duct, especially long runs or ducts with many bends.
- Crushed foil or plastic duct behind the dryer.
- Stuck flap on the outside vent hood.
- Lint screen clogged with dryer sheet film. Wash it with warm soapy water.
- No heat: heating element or thermal fuse on electric dryers; igniter or gas valve coils on gas dryers.
- Moisture sensor bars coated with residue, so the dryer stops too early on auto cycles.
- Only one leg of power on an electric dryer: the drum turns but there's no heat. Check both breakers.
Quick test
Run the dryer on high heat and go outside to the vent hood. You should feel strong, warm airflow. Weak airflow means the duct needs cleaning. Strong airflow but cold air means a heating problem.
When to call a technician
Call if there's no heat, if the dryer smells of burning, if you smell gas, or if it keeps blowing thermal fuses. Replacing a fuse without fixing the airflow means it will blow again.
More on dryer repair, including error codes by brand.