If you know anything at all about how a clothes dryer works, then you know that there need to be good ventilation to the outside of your home so the damp, hot air from the machine can exit, allowing your clothes to dry. If the vent duct has irregularities, it can lead to several problems including condensation leading to water pooling or dripping.
Signs of Condensation In Dryer Vent
Condensation in your dryer vent can manifest itself in several ways, ultimately leading to issues with your dryer’s performance and operation. Here are a few common indications that indicate you have a moisture problem.
- Dampness or Water Around the Vent: One of the most obvious signs of condensation is finding water or damp spots around your dryer vent exterior grill or near the indoor vent.
- Moisture Inside the Dryer: If your clothes are remain damp after a full cycle or the dryer drum feels wet, this is most likely due to condensation within the vent.
- Mold or Mildew Smells: If you get a moldy or musty smell around the dryer it could be an indication that moisture is accumulating in the vent encouraging mold or mildew growth.
- Increased Drying Times: Condensation will also affect the dryer’s efficiency, meaning longer drying times.
- Visible Condensation: In some cases, you might see visible condensation dripping or fogging on walls, windows, or other surfaces.
- Lint Accumulation: Moisture in the vent can often cause lint to clump and matt together and build up, leading to blockages.
Condensation in your dryer vent is not just a nuisance, it’s a serious risk and could potentially lead to serious mold growth or possible fire hazards due to lint build up, so it’s important to address it as soon as you notice it.
With that said, if you notice water in your dryer vent hose, the most likely cause is poor ventilation. The moist air coming from your dryer can’t pass freely from the machine to the outside of your home resulting in condensation inside the dryer vent once the hot air cools.
7 Causes of Water Leaking From Your Vent Hose
There are several reasons your dryer might not be venting properly and causing water in the dryer vent. Below, I will go over these reasons and then give you some advice on how to fix each issue.
The purpose of a dryer vent is to allow the hot, damp air inside the dryer to be extracted to the outside of your home. To facilitate this, the vent hose should be as short and straight as possible and have no kinks or dents in it where lint can become trapped. Let’s explore some of the reasons water might get trapped inside a dryer vent.
1. Dryer Vent Hose Crushed Behind Dryer
Many homeowners like to push their dryers as close to the wall as possible, to save space and align their appliances next to one another or underneath a counter top. This may look aesthetically pleasing but doing so can lead to crushing the vent hose at back of the dryer. If this happens, the airflow from the dryer is restricted, and water or lint will collect inside the hose.
This is the first place I would recommend you investigate. Pull the dryer away from the wall a little, and check the vent duct is free and allowing air to flow. See if that resolves the issue. If the vent hose is permanently dented, crushed or damaged, replace it to restore adequate air flow and eliminate any water pooling issues.
2. Ductwork Is Too Long, Twists or Bends
Ideally, your dryer’s vent hose should be 5 to 10 feet long and as straight as possible. If your ductwork is longer or has twists and bends, it is likely water will collect and gather in the low point along the length of the duct.
The longer a dryer vent is, the longer the hot air has to cool inside the hose, creating condensation. If the vent hose has curves or bends in it, the airflow can become restricted, which also causes condensation inside the vent.
If your outside dryer vent is located more than 10 feet away from the machine itself, you may want to consider changing locations to create a shorter, and more direct vent system that won’t restrict airflow.
3. Dips in Duct Hose Collect Water
Just as twists and bends restrict airflow, dips in the flexible vent hose will also restrict airflow and provide areas for condensation to build. Water runs to the lowest point, and if your dryer vent hose has significant dips in it, any condensation that forms inside the hose will run right into the low spots. The pools of water will narrow the interior diameter of the vent and restrict airflow.
To prevent water in your dryer vent, make sure the hose is as straight as possible using rigid tubing and fixing straps to keep it from sagging. The longer the vent, the more important that you pay close attention to straighten our sagging areas.
4. Using Flex Vent Within Wall Cavity
Some people install flexible dryer hoses inside a wall or ceiling cavity, which generally speaking is not such a good idea. First, a flexible hose has ridges that can trap lint, restricting airflow. Second, if the dryer vent is located inside the wall or ceiling, it makes it very difficult to clean, repair or replace.
If you feel that you have no alterative other then to run duct through interior wall cavities, then opt for a rigid aluminum duct. Metal vent duct has a smooth interior surface without ridges, which means lint is more likely to flow straight through and not gather on the ridges. This makes it a more efficient and safer alternative when routing duct vent inside a dry wall or ceiling.
5. Dirty Or Clogged Dryer Vent
Many people don’t know that they are supposed to clean out their dryer’s vent hose at least once a year. A dryer generates a lot of lint during the drying process, and some of that lint ends up in the lint trap that you empty after each load. Some of the lint, also, travels up inside your dryer’s vent and exits outside of your home. Over time, the lint that passes through the vent will inevitably build up, causing a partial or full blockage that, at the very least, will impede the machine’s drying ability. In extreme circumstances, built-up dryer lint can pose a fire hazard due to its flammable nature.
In any event, a dirty or clogged dryer vent can trap water inside, so if you haven’t cleaned your dryer vent lately, this could be the reason for the moisture you can see coming from the vent. It a simple task to clean the vent yourself using a stiff bristle brush, or alternatively you call a professional to do it for you.
6. Uninsulated Duct Hose Creates Condensation
Sometimes, a dryer vent runs through the attic or crawl space where the hot air from the dryer, meets the cool ambient temperatures within the attic or crawlspace. When the hot air cools it produces condensation, in the same way that that your car windows mists when your warm breath hits the cold glass. This condensation creates moisture build up, drips, and eventually small pools of water form.
The easiest way to prevent this is to either replace the dryer hose with an insulated duct, or wrap your existing dryer hose in fiberglass insulation or lagging to insulate it from extreme temperature fluctuations.
7. Rainwater Entering the External Dryer Vent
This is probably the least likely reason for water in your dryer vent, but it can happen. If the vent cover on the outside of your home is damaged or missing, it can allow rainwater to enter the vent. If your dryer vent hose runs vertically from the outside opening, this can cause water to run back toward the dryer.
As part of your annual dryer maintenance checks, go outside and inspect the outside vent cover, making sure it is firmly fixed in place and free of cracks or other damage. This quick task can prevent major headaches later, so don’t neglect it.
Test The Dryer Duct From The Outside
If you change anything with your dryer’s vent, whether it’s repairing or replacing the hose or simply cleaning it out, you should always check that you still have adequate airflow through the vent. This is a very simple check so there are no excuses for side-stepping it.
Once you have finished working or adjusting your vent, turn the dryer on and go outside and locate the dryer vent cover on the side of your house. Place your hand in front of it and feel for the airflow. You should feel a strong flow of hot air coming from it. If the airflow is weak, it’s a clear sign that something is restricting the airflow and it needs further investigation to identify and fix the problem.
If you can’t find the reason for the weak airflow or you still see water in the dryer vent, call a professional to diagnose and they will have the right level of experience to locate the issue quickly and fix it.
Removing Water From Your Dryer Vent
Removing water from an existing vent duct is a very simple task as long as the duct is not routed behind a well or though the attic:
- Unplug the Dryer: Safety is paramount; ensure your dryer is unplugged before starting the process.
- Detach the Dryer Vent: Depending on your dryer, you may need a screwdriver, hex key or other tool to disconnect the vent. Typically, the vent is attached to the dryer at one end and also attached to the wall at the opposite end.
- Inspect the Vent: Look for any visible water or blockages within the duct. If water is visible, try tilting the vent to allow water to flow out and drain into a bucket.
- Vacuum the Vent: Using a shop vacuum or a special dryer vent cleaning kit like this one, vacuum out the vent to remove any water or excess lint that may be causing blockages.
- Air Dry: Allow the vent to completely air dry before reconnecting it to the dryer. You can speed up this process using a hairdryer to blow warm air through the duct, but be sure the vent is entirely dry before it’s reconnected.
- Reconnect the Vent: Once the vent is dry, reconnect it to your dryer and the wall outlet, making sure it is firmly attached at both end and check that there are no signed of sagging or blockages.
- Address Recurring Issues: If water in your vent is a recurrent problem, you may need to insulate the vent, reroute it, or make other changes to prevent condensation from occurring.
Condensation in Dryer Vent Solved
In summary, the reason there is water leaking from your dryer vent is that it has poor ventilation. Poor dryer ventilation can be caused by excessively long or curvy vent hoses, lint buildup, crushed tubing, or extreme temperature fluctuation causing condensation. To avoid the issue of water in the dryer vent, make sure your dryer’s hose is as short and straight as possible and clean it regularly to prevent blockages.
Andy has over 8 years of experience working on residential household appliances, performing diagnostics, and repairs across most major brands. He graduated from the Denver Institute of Technology, is NASTeC certified, and has worked for Mr. Appliance. Andy has contributed to features on major publications including Better Home & Gardens, Family Handyman, and Yahoo.com.