what happens when Dryer Vent Is Blocked – 4 causes and how to fix

Dryer vents require regular cleaning to prevent them from getting blocked. What happens when a dryer vent is blocked? We’ll explore everything you need to know about dryer vents, why they get blocked, and how to clean them.

Dryer vents get blocked due to a buildup of lint and dirt, either from the inside of the machine or from the exterior through an exposed vent cover. You can use a vacuum cleaner and a long brush to clear that blockage by first disconnecting the vent at both ends. Alternatively, you could also hire a professional service provider to do it for you.

What Happens When Dryer Vent Is Blocked?

To know whether or not your dryer vent is blocked, look out for these signs:

1. Clothes Take Longer To Dry

One of the most apparent tell-tale signs that your dryer vent is blocked is that clothes take much longer to drive. 

To understand why this happens, let’s quickly recap how a dryer works. Your dryer generates heat and forces it through the drum where your wet clothes are tumbling. As that happens, moisture is removed from your clothes. Then, the same hot air is forced through your dryer vent and out of the building.

Related: How Does A Samsung Steam Dryer Work?

When the airflow is reduced by the blocked vent, the moist air will have a much more challenging time escaping the dryer. Therefore, it takes much longer than usual for your clothes to get dry.

2. Too Much Heat After Drying

It’s entirely normal for the dryer and your clothes inside to be warm once the drying cycle has ended. However, if both of them are excessively hot, that’s another sign that your dryer vent is blocked.

That is related to what was mentioned in the previous point: a blocked vent reduces airflow out of the dryer, so heat (and moisture) can’t escape efficiently.

As a result, both your clothes and the appliance itself overheat. Overheated clothes can lead to excess shrinking and damage to the garments themselves.

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3. Burning Smell

When people set and forget their dryers, they might not notice that it takes longer than usual to dry their clothes. That might also make it easier to overlook an overheating dryer, as the appliance will cool down when they eventually empty it.

There is, however, one sign of a blocked vent that’s hard to ignore: a burning smell. When air can’t escape through the blocked vent and the dryer and clothes inside it, overheat. Temperatures might rise so high that a burning smell might come from the dryer and its contents.

Worse still, the smell might come from the vent itself overheating, which is a very high fire risk. 

4. No Airflow At The Vent Cover

A blocked dryer vent is also noticeable on the building’s exterior at the vent cover. No matter what type of vent you have, you’ll notice little or no airflow coming out of the vent cover when the dryer is in operation.

That’s a clear sign that the vent is blocked.

5. Fire Risk Increases

When a dryer vent is blocked, the risk of a fire increases significantly. Most dryer vent blockages are caused by lint which are the fibers that come off from clothes tumbling in the dryer. 

Sure, the lint filter is meant to capture most of that lint, but a lot of it gets into the vent regardless. That lint is at risk of igniting and causing a fire.

Besides that, part or all of the dryer’s vent is likely to consist of flexible ducting. In many cases, flexible ducting is combustible and raises that fire risk even further.

Why Is My Dryer Vent Blocked?

If your dryer vent is blocked, it’s likely for the following reasons:

Related: Why Does Dryer Vent Keep Getting Clogged?

1. Lint Buildup

The most likely reason that a dryer vent gets blocked is that there’s a buildup of lint.

As mentioned before, lint consists of tiny fibers that come off the clothes tumbling inside the appliance. The lint filter inside the machine effectively removes most of the lint that passes through, but certainly not all of it.

Over time, that lint will build up inside of the dryer vent. That’s especially true if the vent has lots of turns or large ridges inside of it. These traits can cause the vent to trap lint at a higher rate, leading to quicker and more severe blockages.

2. External Dirt And Dust

Quite often, the importance of the vent cover on the building’s exterior is underestimated. This cover exists to protect dirt, dust, and anything else from the outside to enter the vent.

Still, this does happen. Perhaps the vent cover is insufficient or damaged. For instance, the louvers on some vents could get stuck in the open position, leaving the entire vent exposed to the elements.

All of that external dirt and dust could build up inside the vent restricting airflow. That is also made worse when combined with the lint buildup caused by the dryer described earlier.

3. Vent Cover Is Stuck Closed

A vent cover that’s stuck open can get blocked quite quickly. However, the same could happen even when the vent cover is stuck in the closed position.

what happens when dryer vent is blocked

The reason for this is very straightforward: when the vent cover is closed, airflow is restricted. The lint that should be forced out of the cover has nowhere to go, so it settles and builds up inside the vent instead.

4. Kinked Vents

Lastly, dryer vents can also get blocked due to kinks somewhere along the line. Ideally, dryer vents should be placed as straight as possible with few or no bends or corners.

Kinked vents can happen in many ways. For instance, your dryer might be pushed up against the back wall so close that it presses up against the vent, restricting airflow.

Some users have dryer vents that travel across the home, perhaps through the attic. There is the danger of boxes or other items falling onto the vent and blocking airflow in those situations.

How Do You Unclog A Dryer Vent?

  • Unplug the vent: To unclog a dryer vent, you’ll want to disconnect it from both sides (i.e. the back of the dryer and from where it terminates to the building’s exterior). That will make it much easier to remove more significant blockages and clean the vent thoroughly.
  • Vacuum and brush: If the dryer is short enough, you can use a vacuum to remove everything causing the clog. Then, you can also clean out any remaining dirt, dust, or lint using a brush.
  • Dryer vent cleaning kit: For longer vents, you’ll want to consider investing in a vent cleaning kit. These kits include specialized brushes extending by up to 30 feet or more to clean lengthier dryer vents. These kits can be purchased on Amazon, or at your local hardware store in the appliance department.
  • Professional vent cleaning services: Of course, there’s also no shame in hiring a professional to unclog your dryer vent for you. Check your local area for businesses that specialize in cleaning and servicing dryer ducts.

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Related: Dryer Vent Repair – Should You Fix It By Yourself?

Can A Blocked Dryer Vent Cause A Fire?

Yes, a blocked dryer vent can cause a fire. According to the US Fire Administration, thousands of dryer fires happen each year, and 34% of them are caused by a failure to clean the dryer.

The reason for this is apparent. When the hot air from the dryer is unable to escape, it will cause the dryer, its vent, and anything inside to overheat.

Assuming you’re using a cheaper, non-fire retardant vent, its materials could be the first to combust and start a fire. The same can also happen for clothing or other flammable fabrics that you might have loaded into the dryer drum. 

Most importantly, the lint accumulation in the vent can also overheat and burn, leading to a fire starting from your laundry room.

Can You Clean A Dryer Vent Yourself?

Yes, you can clean a dryer vent all by yourself! The only tools you’ll need are a vacuum cleaner and a brush that’s long enough to reach into your dryer vent. 

To protect yourself, you’ll also want to wear some kind of face and mouth covering to prevent being affected by the dust and lint that you’re cleaning out of the vent.

You can easily disconnect the dryer vent from the back of the appliance and its termination point at the wall. Then, you’ll just need to vacuum and brush out any dirt trapped inside.

Related How Often To Clean Dryer Vent?

Can You Use A Leaf Blower To Clean Dryer Vent?

Yes, you can use a leaf blower to clean your dryer vent.

To do this, disconnect the dryer vent from behind the dryer, but leave the other end connected to the dryer vent cover. Then, slide the blower nozzle into the vent and create a tight seal around it using duct tape or something similar.


You must only use the leaf blower to push air towards the outside of the structure, and never the other way around. You don’t want to blow all of the lint and dirt back into the home, which will be a nightmare to clean up.

  • Start Soft: Leaf blowers can be extremely powerful, which is why you’ll want to begin with the lowest setting possible when cleaning your dryer vent. If necessary, and only if you’re sure the vent can handle the strong airflow, then you can increase the leaf blower’s power. 

How Often Should Dryer Vent Be Cleaned?

Ideally, you should clean your dryer vent thoroughly once or twice a year. You should do so more often if you use your dryer heavily, such as in a home with large families.

How Often Should You Replace Your Dryer Vent Hose?

Dryer vent hoses do not need to be replaced unless they are damaged. Torn hoses or those with holes in them should be replaced, as they prevent air from being channeled directly to the outside of the building.

A damaged vent could cause lint, dirt, and excessive heat to escape inside the home rather than be pushed outside through the vent cover.

How Much Does It Cost To Get Dryer Vents Cleaned?

Across the United States, the national average cost for professional dryer vent cleaning is $145. At a minimum, you could find service providers charging at least $90, while higher-end cleaning can reach up to $550.

Several factors affect the final price for dryer vent cleaning. That will include the length of the vents that need to be cleaned and the severity of the blockage.

Always be sure to discuss prices with the service provider before agreeing to them working on your vents.

Is A Flexible Dryer Vent Safe?

No, flexible dryer vents are not as safe as rigid ones. Flexible dryer vents cause lint and dirt to build up faster than rigid ones.

Still, they are a necessity in some cases. That’s why your vents should consist of as few flexible parts as possible, while the majority should consist of rigid parts.

Related: Why Is Steam Coming Out Of The Dryer Vent?

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