Clothes dryer taking too long: airflow, loading, and safe lint maintenance

What the symptoms can tell you

If clothes need multiple cycles or remain damp while the dryer cabinet becomes unusually hot, restricted airflow is a likely cause. Moist air may be trapped, causing the dryer to stop and restart as safety limits are reached.

If the drum air stays cold throughout the cycle, the problem is more likely in the heating circuit or power supply than in the vent. Poor exhaust flow may also show up as a musty smell, a vent hood flap that barely moves, or excess lint around the chute, drum seals, or room.

Check the load and what goes into the dryer

An overloaded drum can keep clothes from tumbling freely and block warm-air circulation. Aim to fill the drum about one-half to three-quarters full.

Heavy items such as towels or denim mixed with lightweight synthetics can make sensor-dry cycles stop too early or make drying times uneven. If clothes enter the dryer soaking wet, a washer spin-speed or pump problem may be extending the drying time.

Safe lint and airflow maintenance

Clean the lint screen before or after every load. Fabric softener and dryer-sheet residue can clog its mesh, so periodically wash the screen with warm, soapy water and a soft brush; let it dry completely before putting it back.

Every few months, remove lint below the screen housing with a dryer-lint vacuum attachment or flexible brush. Check that the transition duct behind the dryer is not pinched or crushed, and that the outdoor vent hood opens freely and is clear of lint, debris, or bird nests.

• Replace flexible plastic or foil accordion-style transition ducting with rigid or semi-rigid metal ducting. Plastic and corrugated foil can kink, crush, and trap lint, restricting airflow and creating a serious fire risk.

Safety before moving or cleaning

Before pulling the dryer away from the wall or disconnecting its transition duct, unplug it or switch off its dedicated circuit breaker. When reconnecting, make sure the duct is securely clamped to both the dryer collar and the wall connection before restoring power.

Never put items contaminated with cooking oil, gasoline, paint thinner, or flammable cleaning agents into a heated dryer cycle, even after washing. They can pose a spontaneous-combustion risk.

When to stop and call a professional

Call a qualified technician or professional duct service if the vent run goes vertically through multiple stories, an attic, or a roof jack; these runs need specialized cleaning equipment. Also call if the drum air stays cold or only partly heats.

No-heat causes can include a failed leg of an electric dryer's 240-volt supply, an internal heating element or bias resistor fault, or—on a gas dryer—an ignition problem or failed solenoid coils. If airflow is still weak with clear ductwork, an internal component may be at fault. Do not attempt internal repairs.

• Possible internal causes include a cracked or slipping blower wheel, worn drum support seals, defective cycling thermostats, or a blown high-limit thermal fuse.

Frequently asked questions