5 Causes of a Leaking Dryer Vent

A dryer vent on the outside of a beige house.

A leaking dryer vent can cause several problems such as mold, mildew, and water damage in your home. This problem is not uncommon and is seen in most households at some point or another. There are several possibilities to consider when you find that your dryer vent is leaking.

1. Blocked Vent

A blocked vent is a common cause for dryer vent leaks. Stray lint and fabric may accumulate in the vent over time. This creates a blockage in the pipe, blocking the flow of air. The hot, moist air that is exhausted by the dryer has nowhere to go.

As a result, it could condense and result in a water leak. To fix this problem, clean the dryer vent pipe with a brush to remove all the accumulated lint. This will improve the passage for hot air.

2. Condensation

A drying machine.

Condensation on the dryer vent pipe is a problem most commonly seen in colder climates. As the warm air from the dryer is vented to the outside, it must be protected from the cold temperatures outside.

If your dryer vent pipe is not properly insulated, the air that is being vented out will turn into water when it comes into contact with the cold pipe outside. This results in condensation and dripping water.

To remedy this, you must insulate your dryer vent pipe along its entire length. This will ensure that the hot air from the dryer does not undergo temperature fluctuations, thereby preventing condensation on the vent pipe.

3. Broken Flapper on Outer Opening

Dryer vent pipes have flappers on the outer edge of the pipe. You can find this flapper on the edge of the pipe where the hot air is emanating to the outside. This flapper opens when the air from the dryer needs an outlet.

At all other times, it must remain securely shut. If this flapper is not shutting properly, it can let in rainwater, snow, or frost from the outdoors, which can then travel inside and cause a leak near your dryer.

To remedy this, you must check the flapper outdoors to see if it opens and closes properly. If it does not, you will have to get it replaced.

4. Vent Exhausts Into the Attic or Garage

A laundry room with washing and drying machines.

Dryer vents should be ventilated outdoors or through the roof. Some homes have dryer vents that exhaust to the attic or garage. There are several problems with these types of installations.

The outer part of the vent pipe may be difficult to access and check for problems. When the hot air is vented to such an enclosed area, it could lead to moisture problems. This can cause dryer vent leaks and also mold, mildew, and moisture accumulation on the structure.

5. Holes or Cracks in Vent

A damaged dryer vent pipe can also be the cause of a leak. It could cause water problems because of condensation or water that is being leaked in from the outdoors or other pipes near the vent pipe.

Hopefully you were able to discover why your dryer vent is leaking. This seemingly small problem is an important one to catch and correct early on.