Dryer runs but clothes take a very long time to dry; display shows AF (restricted airflow) error.

Safety first: Unplug the dryer before inspecting the venting. If it is a gas dryer, also shut off the gas supply valve.

Steps to improve airflow:

• Clean the lint screen: Remove the lint filter and clean off all lint. Wash with warm soapy water if it has fabric softener residue, then dry completely before reinstalling.
• Inspect the vent hose: Pull the dryer away from the wall. Check the flexible vent hose for kinks, crushing, or heavy lint buildup. Detach it from the dryer and the wall and clean it thoroughly with a vent brush or vacuum.
• Check the exterior vent hood: Go outside and verify the vent hood flap opens fully when the dryer runs. Remove lint, bird nests, or debris blocking the outlet.
• Verify vent length and routing: Ensure the vent run is as short and straight as possible, with minimal elbows. Replace thin plastic or foil vent with rigid or semi-rigid metal ducting.
• Test operation: Reconnect the vent, restore power (and gas if applicable), and run a timed dry cycle. Confirm strong airflow at the outside vent and check if the AF code clears.

If airflow is still weak after cleaning and shortening the vent, have a technician inspect the blower wheel and internal ducting.