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I have a new house (Oct 2020, am first occupant) and a new LG dryer (bought it when I moved in). The duct runs to the outside a few feet away, where there's a screen and a flap (lift the flap and there's a screen covering the termination of the duct). Lint constantly accumulates on the inside of that screen and needs to be cleaned out; we find this out when the dryer registers an airflow error and stops drying effectively. I've cleaned the duct and screen three times and had it done professionally once, all in the 8 months we've lived here.

We had an LG support tech come look at the dryer and he just insists we need to clean it, and basically didn't believe us when we said we'd done that only a month before. He also suggested it was a problem with the duct, but I don't get that either: the duct's job is transport air to the outside; it's doing that effectively, but the screen is full of lint because the lint can't pass through it. It can't be the case that things are functioning right.

My theory is that something is wrong with the dryer that's causing lint not to get caught in the lint trap and instead get pumped in large quantities through the duct, which of course accumulate at the screen. Is that right? And if so, what are the troubleshoot steps?

snickersnack
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    Does the dryer's lint trap trap lint? Do you check the dryer's lint trap before use? Might be a bypass for dryer's trap that is open. – crip659 Jul 03 '21 at 13:15
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    Some lint *always* makes it past the lint filters. The answer provided by Jeff Wheeler is correct - don't have a second lint trap (screen) on the output of the vent. – Ecnerwal Jul 03 '21 at 17:16
  • Are you drying your clothes for too long? Or are they materials that generate a lot of lint? – Criggie Jul 04 '21 at 00:13
  • re: lint trap: we always check the lint trap. It _seems_ like it's not trapping as much lint as our previous dryers did, but it's hard to say for sure. Certainly it's not crammed with the stuff on each run. And, well, yeah, we create a lot of lint with tons of kids' cotton clothing. Never had this issue before. – snickersnack Jul 04 '21 at 01:41

3 Answers3

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Remove the screen from the exterior end of the dryer vent. It is a danger, violates building code in most areas, and should never have been installed.

Dryer vents are meant to blow untrapped lint outside. That's why they need to be unscreened.

From 2015 IRC M1502.3 Duct termination (emphasis added):

Exhaust ducts shall terminate on the outside of the building. Exhaust duct terminations shall be in accordance with the dryer manufacturer’s installation instructions. If the manufacturer’s instructions do not specify a termination location, the exhaust duct shall terminate not less than 3 feet (914 mm) in any direction from openings into buildings. Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.

Jeff Wheeler
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    Blow ye lint, blow! – Willk Jul 03 '21 at 19:21
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    Whilst this is the sensible answer, it refers to (I believe) U.S. standards. I don't know how relevant that is to OP, who could be anywhere in the world, U.K. I suspect. Once again, location could be included, and may well have an impact on answers. – Tim Jul 04 '21 at 07:41
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    @Tim Good point. I am in the US, though, and I double checked this answer against my state's specific regulations, and they match – snickersnack Jul 04 '21 at 15:24
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    @Tim: A screen over the termination of a dryer vent is a fire hazard no matter _where_ you live. – Vikki Jul 04 '21 at 17:10
  • You may still have to clean the back-side of the backdraft damper from time to time. – jwdonahue Jul 04 '21 at 20:26
  • @Tim certainly I’ve never seen a *screen* on a dryer vent. I’ve seen a flappy cover, but that’s different. I don’t think the distance from building openings applies (I mean, my house (terraced) house doesn’t even have a location 3ft from building openings!) – Tim Jul 05 '21 at 20:55
  • Even the vents that have just a few plastic bars across to prevent animals from getting in, it increases the chance that it will clog. – rtaft Jul 09 '21 at 18:47
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    Just following up here: I contacted the house's builder, he agreed the screen shouldn't have been installed, and has replaced it. – snickersnack Jul 12 '21 at 15:55
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While the accepted answer details safety/code issues with the venting (and don't forget to have the inside of the dryer serviced as well - if you trigger a fire or make the TCOs inside activate to prevent one then your warranty is voided), it is a symptom. The root cause of your problem is not the dryer.*

(*Check that your dryer doesn't have any sharp edges or other physical damage inside and that the basket properly matches with the door seal and the back wall if applicable. It should not wobble if you grab the fins and pull.)

Lint is the remains of clothing after washing. In other words, what you get out of your dryer is what is left of your clothes after washing.

If you have excess lint in your dryer it is because your wash is causing excessive damage to your clothes. You need to start using a less destructive detergent.

Cheap detergents are not your friend. (I personally recommend and use Woolite, but YRMV.)

Other factors to consider are:

  • Hard and improperly-balanced water systems.
  • Older washers are typically more violent with their loads. Modern HE top-load washers without a big agitator are the best bang for your buck.
  • Any extra sand/dirt/contaminant that gets into the wash with your clothing.

The extra expense of a better detergent easily offsets the cost of buying new clothes on a regular basis.

Source: I was a very highly-trained appliance repair technician before my health took a dive.

Dúthomhas
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    "The extra expense of a better detergent easily offsets the cost of buying new clothes on a regular basis", LOL, children usually tear-up the clothing or just grow out of them, much faster than any wash/dry process. – jwdonahue Jul 04 '21 at 20:29
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    @jwdonahue You'd be surprised, then. If you are getting a thick enough mat of lint to make a blanket with every load then your children need to step up their game... – Dúthomhas Jul 04 '21 at 20:37
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    @Dúthomhas Lint are the result of damaged fibers. The drying process merely frees them from the cloth. You're making an assumption wrt to the quantity of the lint. It doesn't take much lint to clog a fine enough screen. I am just pointing out that your cost/benefits analysis probably doesn't hold here. – jwdonahue Jul 04 '21 at 20:46
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    @jwdonahue I should reiterate then that my info comes from the people who make these machines. The wash process is actually a pretty impressive sequence that is designed to loosen the weave of fabric so that the detergent can chemically bind with dirt and grease. The dryer itself tightens the fabrics back up, and the softener is a thin layer of new oils to make things feel all soft and flex easily. Harsh detergent and violent scrubbing, whether from kids or otherwise, is where lint comes from. – Dúthomhas Jul 05 '21 at 00:25
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    @Dúthomhas, ya, they said that for a very long time, then they finally removed the abrasive agitator and suddenly our cloths started lasting longer ;). I suspect chorine and other water treatments, plus mineral deposits in the clothes and water are the greatest cause of damaged to cotton fibers in the wash, but even that is relatively mild, compared to what a child can do their clothes on the average day. – jwdonahue Jul 05 '21 at 05:52
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    Silk and wool are a different story, as they depend on proteins that can be destroyed by enzymes. The OP's vent issue is caused by a screen placed where it should not be, not by excessive damage to their children's clothing. – jwdonahue Jul 05 '21 at 05:52
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    Yes, very true. My answer was meant to apply to general troubleshooting well beyond OP's stated issues. I should have been more clear about that. I still think our aside has been instructive in the context of looking up problems with excessive lint on SE, though... – Dúthomhas Jul 05 '21 at 15:33
  • I think your answer is insightful, but you might consider editing it to make it clear that the information you've provided is not a solution/answer to the original question in this post; rather it's, as you said, more general about the operation of clothes washers. – Jeff Wheeler Jul 05 '21 at 18:13
  • Disagree - OP clearly states that excessive lint after recent servicing is an issue. My post may not answer the exact reason his specific problem occurred (because the other answer does and OP has accepted it), but it details common issues to observe when excessive lint presents. A more comprehensive list is of value to future visitors troubleshooting _their_ specific problem. – Dúthomhas Jul 05 '21 at 21:31
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While being aware of the current answers, I'd like to provide a supplementary possibility that I experienced myself.

I bought an LG dryer 6 months ago. Immediately started having all the same symptoms where no matter how "clean" we would make the dryer vents and all ... the error codes would still pop up and the dryer wouldn't dry!

It turns out that the dryer wasn't receiving enough voltage from the outlet. A bad breaker switch at our main box was causing only ~100 volts of electricity from the outlet. We replaced the breaker to the dryer's outlet and the dryer worked just fine!

Tested the outlet w/ just your average voltmeter you can find at any hardware store. And the only thought I had to test the voltage was because we had already been doing a lot of electrical fixes on my house. (It's on the older side for american houses.)

CS Eliot
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