Start the dryer and check the vent opening
The simplest way to run a dryer vent is to turn on your dryer and watch where the air comes out. Most dryers have a vent hose that runs from the back of the machine to either an exterior wall or a duct that leads outside. When you start a drying cycle, warm, moist air should flow steadily out of that opening — you should feel it with your hand if you stand near the exit.
If you feel little or no air movement, the vent is likely clogged. A blocked vent forces the dryer to work harder, takes longer to dry clothes, and creates a fire hazard because lint builds up inside the machine and ductwork. Before you run the dryer again, you need to clear the blockage.
Key Takeaways
- A working dryer vent should release warm, moist air steadily to the outside; weak airflow means the vent is clogged and needs cleaning.
- Clean the lint trap before every load and inspect the vent opening outside at least once a month to catch lint buildup early.
- Lint accumulates fastest in flexible metal hoses and elbows, so straighten the vent path and replace kinked or crushed hoses.
- If the vent is clogged deep inside the ductwork, use a dryer vent brush kit or hire a professional to clear it safely.
Clean the lint trap every single time
The lint trap is the first line of defense. It sits inside the dryer door or on top of the machine, depending on your model. Pull it out after every load and wipe the lint off with your fingers or a dry cloth. A full lint trap blocks airflow when ready and forces the dryer to reheat the same air instead of exhausting it.
Even a trap that looks mostly clean can hold enough lint to slow drying time by 20 to 30 minutes per load. Emptying it takes five seconds and costs nothing. If you skip this step, you will see longer drying times, higher energy bills, and a much higher risk of lint fire inside the dryer cabinet.
Check the vent opening outside monthly
Walk to the outside wall where your dryer vent exits and look at the opening. It should be clear, with no lint, leaves, or debris blocking the flapper or screen. If lint has built up around the opening or the flapper does not swing freely, the vent needs cleaning from the outside in.
Lint sticks to the inside of the vent hose and ductwork over time, especially in the first few feet after the dryer. A vent that looks clear from outside may still be partially blocked inside. If you notice lint around the opening, assume the interior is also accumulating lint and plan to clean the full vent run within the next week or two.
Straighten the vent hose and replace kinked sections
Flexible metal hose is the most common vent material, but it traps lint easily if it sags, kinks, or has tight bends. The ideal vent run goes straight from the dryer to the outside wall with as few turns as possible. Each elbow or bend slows airflow and collects lint.
If your hose has a kink or crush, replace that section with new flexible metal hose. Avoid plastic hose entirely — it melts and is a fire hazard. Rigid metal ductwork is better than flexible hose if your layout allows it, because lint slides through more easily and does not accumulate as fast. If the hose sags between the dryer and the wall, support it with a strap or clamp every 3 to 4 feet so it stays level and lint does not pool inside.
Use a dryer vent brush to clear deep clogs
If airflow is weak and the lint trap and outside opening are both clear, lint has built up inside the ductwork. You can clear this yourself with a dryer vent brush kit, which includes a long flexible brush and rods that screw together to reach deep into the vent.
Disconnect the vent hose from the back of the dryer, insert the brush into the opening, and push it through toward the outside, twisting as you go. The brush will catch lint and pull it back out. Work slowly and do not force the brush — if it gets stuck, back it out and try a different angle. Once you have pushed the brush all the way through, reconnect the hose and test the dryer again. You should feel much stronger airflow at the outside opening.
If the vent is so clogged that the brush will not move, or if the ductwork is buried in a wall and you cannot reach it, hire a professional vent cleaning service. They have powered equipment that can clear blockages you cannot reach by hand.
Run a test cycle and feel the airflow
After cleaning, start a short drying cycle and walk to the outside vent opening. Hold your hand near the exit and feel the air pressure. It should be warm and steady, not weak or intermittent. If airflow is still poor, the vent may have another clog further down, or the hose may still be kinked or crushed somewhere along its run.
Check the entire length of the hose from the dryer to the wall. Look for any section that is bent, flattened, or pinched. Straighten it or replace it if necessary. Once airflow feels strong and warm, your vent is working correctly and your dryer will dry clothes in the normal time.
Maintain the vent every month to prevent future clogs
The easiest way to keep a dryer vent working is to prevent lint from building up in the first place. Empty the lint trap before every load — this is non-negotiable. Check the outside vent opening once a month and wipe away any lint or debris. If you see lint accumulating, clean the hose with the brush kit before the clog becomes severe.
Replace the vent hose every 3 to 5 years even if it looks clean, because lint embeds itself into the interior walls over time and airflow gradually declines. A new hose costs $15 to $30 and takes 10 minutes to install. This small investment prevents the slow drying times and fire risk that come with an aging, lint-filled vent.
Frequently Asked Questions
Can I use a shop vacuum to clean out the dryer vent?
A shop vacuum can remove loose lint from the outside opening or the first few feet of hose, but it will not reach deep clogs inside the ductwork. A dryer vent brush kit is more effective because it can push through the entire length of the vent. If you use a vacuum, disconnect it before the brush reaches the dryer itself, because the suction can damage the dryer's internal components.
How often should I have my dryer vent professionally cleaned?
If you clean the lint trap every load and check the outside opening monthly, you may never need professional cleaning. However, if your vent is buried in a wall, has many elbows, or you notice lint buildup despite regular maintenance, a professional cleaning once a year is reasonable. Some people go years without needing it; others with poor vent design may need it every 6 to 12 months.
What if my dryer vent goes into the attic instead of outside?
Venting into the attic is not safe and should be changed. Moist air from the dryer condenses in the attic, promoting mold and rot in the wood framing. Code requires dryer vents to exhaust to the outside. If your vent currently goes to the attic, plan to reroute it through an exterior wall or roof. This is a job for a contractor if you are not comfortable working with ductwork and making holes in your home.
Why does my dryer still take a long time even after I cleaned the vent?
A clogged vent is the most common cause of slow drying, but not the only one. Check that the lint trap is not torn or damaged, because a broken trap lets lint bypass the filter and clog the vent again quickly. Also verify that the dryer is level — if it tilts, moisture does not drain properly. If the vent is clear and the trap is intact, the heating element may be failing, which is a repair that requires a technician.