Dryer Not Heating? Start Here
A dryer that tumbles but doesn't heat is one of the most common appliance complaints. The number one cause? A clogged lint vent. Cleaning it takes 15 minutes and costs nothing — and it's also a fire safety issue (dryer lint fires cause 2,900 house fires per year).
What's Happening
Dryers heat air and blow it through tumbling clothes to evaporate moisture. The hot, humid air exits through the vent duct to the outside. When the vent is clogged with lint, air can't escape, the dryer overheats, and a thermal fuse blows to prevent fire. The thermal fuse is a one-time safety device — once it blows, the dryer won't heat until it's replaced. Gas dryers may also lose heating if the igniter or gas valve fails.
What to Check
- Clean the lint trap. Pull out the lint screen and clean it thoroughly. If you use dryer sheets, wash the screen with soap and water — dryer sheets leave a film that blocks airflow. Hold the screen up to light: if you can't see through it, it needs washing.
- Check the vent duct. Disconnect the flexible duct from the back of the dryer. Look inside — if it's packed with lint, that's your problem. Clean the entire duct run from the dryer to the exterior vent with a dryer vent brush (long flexible brush, $10-20). Also check the exterior vent flap outside your house and remove any lint or debris.
- Check if you have power (electric dryer). Electric dryers need a 240-volt circuit with two breakers. If one breaker trips but not the other, the dryer will tumble but not heat. Check your breaker panel for two linked breakers labeled "Dryer" — make sure both are fully ON.
- Check the gas supply (gas dryer). Verify the gas shutoff valve behind the dryer is fully open (handle parallel to the gas line). If you turned it off for some reason, it needs to be turned back on.
- Run a test cycle. After cleaning the vent, run the dryer for 10 minutes on high heat. Go outside and check the exterior vent — you should feel strong, warm airflow. If airflow is still weak, there may be a blockage deeper in the duct or the duct run is too long.
Call a Pro If
- Cleaning the lint trap and vent duct didn't restore heating
- You smell gas near the dryer (shut off gas, ventilate, call gas company)
- The thermal fuse blew (dryer vent cleaning is still needed to prevent recurrence)
- The dryer vent duct is routed through walls and you can't clean it yourself
Frequently Asked Questions
Why does my dryer run but not dry clothes?
Almost always a clogged vent duct. Hot air can't escape, the dryer overheats, and a thermal fuse blows. Clean the vent from the dryer to the exterior wall.
How often should I clean my dryer vent?
At least once a year. If you notice clothes taking longer than one cycle to dry, clean it immediately. Homes with pets or heavy laundry use may need cleaning every 6 months.
Can a clogged dryer vent cause a fire?
Yes. Lint is extremely flammable. Clogged dryer vents cause approximately 2,900 house fires per year. This is a genuine safety concern, not just an efficiency issue.
Gas vs. Electric — Not Sure Which Component to Check?
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