The LG Flow Sense warning indicates a major blockage in your home exhaust ducting. It is a safety feature designed to prevent fires and poor drying performance by detecting restricted airflow. You must clear the lint from your wall ducts to resolve this issue.
I get called out for this one probably three or four times a week. Most homeowners think the dryer's broken, but it's actually doing its job perfectly by warning you. Ignore it long enough and you're looking at a burned-out heating element, clothes that never fully dry, or worst case, a lint fire inside your walls. That last one is not a drill.
LgDryerSeverity: moderate95% DIY Success
Time to Fix
20–60 min
Difficulty
beginner
Parts Cost
—
Tools Needed
Phillips #2 screwdriver, Flathead screwdriver
What Does the FLOW-SENSE Code Mean?
Nine times out of ten when I pull up and see that Flow Sense light, it's lint packed into the elbow right behind the machine or a bird nest blocking the cap on the outside wall. Sometimes it's a duct run that's just too long with too many bends for the motor to push air through. The sensor measures how hard the blower has to work. When it's straining, it tells you.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Lint buildup in wall duct70%
Kinked or crushed transition hose20%
Blocked exterior wall cap10%
Symptoms You May Notice
Flow Sense indicator shows 3 or 4 bars and stays lit the entire cycle, not just at startup.
Towels and jeans coming out damp after a full 50-minute cycle and you're basically running every load twice.
The top of the dryer cabinet gets uncomfortable to touch within 20 minutes of starting a load, way hotter than it should be.
The laundry room or closet feels noticeably humid and steamy while the dryer's running, like the moisture isn't going anywhere outside.
Dryer shuts itself off early and the load is barely warm.
Can you reset a Lg dryer to clear the FLOW-SENSE code?
There's no button sequence to clear Flow Sense. It's not a stored fault code, it's a live reading of what's happening right now. So once you've cleared the blockage, just run a normal cycle. The sensor checks backpressure continuously, and as soon as it reads normal resistance, the bars drop and the warning goes off on its own. If it doesn't clear after a full cycle, the blockage is still there or somewhere else. Go back and dig deeper.
Tools Required for Diagnosis
Phillips #2 screwdriverFlathead screwdriverVacuum with long flexible crevice attachmentRotary dryer vent cleaning brush kitFlashlightWork gloves
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
Frequently Asked Questions
Why is the Flow Sense light still on after I cleaned the lint filter?
Because the lint filter is just the first inch of a duct system that might run 20 feet through your walls before it exits the house. Think of it like cleaning just the opening of a garden hose while the rest of it is kinked shut. The filter being clean is good, but Flow Sense is measuring the whole path all the way to the exterior vent cap. The real blockage is almost always deeper in, usually the elbow right behind the machine or the wall duct itself. Do the bypass test in Step 4 and it'll tell you exactly where to look.
Can I bypass or disable the Flow Sense warning?
Honestly, no. And you really don't want to. This isn't some annoying false alarm, it's the dryer telling you there's an airflow problem that's actively going to burn the machine out or start a fire. Dryer vent fires cause over $200 million in property damage every year according to the CPSC, and most of them were preceded by exactly this kind of warning being ignored. Even if clothes are technically still drying right now, your heating element is working way harder than it should and its lifespan is shrinking fast. Fix the duct. That's the only right answer here.
What does it mean if I see 4 bars on the Flow Sense display?
Four bars is as bad as it gets. That means the sensor is detecting 80% or more restriction in the exhaust path, which is basically a near-complete blockage. At that level the dryer will cut the heater off to protect itself, so your clothes tumble in cold or barely warm air and come out damp no matter how long you run it. Two bars means partial blockage and you've got a little time to deal with it. Four bars means deal with it today, not next weekend. Don't run it again until you've found the clog.
Will a Flow Sense warning cause my clothes to stay damp?
Absolutely, and it gets worse the longer you let it go. When air can't flow through freely, moisture just stays trapped in the drum circulating around your clothes instead of venting out. I've had customers tell me they've been running every load twice for months because they figured the dryer was just getting old. Nope. It's the duct every time. The moisture sensor bar inside the drum also reads wrong when airflow is off, so the dryer thinks the load is dry when it's still soaked. Towels and jeans are the first things you'll notice because they hold the most water.
Is the Flow Sense sensor itself likely to be broken?
Rarely. In 15 years I've probably replaced three or four control boards for a truly false Flow Sense reading, and each time we'd already proven the duct was clear first. The sensor's doing its job correctly 99% of the time. If you've cleaned the whole duct run, replaced the transition hose, confirmed the exterior vent is wide open, and done the bypass test with the hose completely disconnected and it still shows full bars, then yeah, call a tech because you might have a sensor or control board issue. But exhaust everything else first. That's always a last resort.
How often should I have my dryer duct professionally cleaned?
Every one to two years is the standard answer, but it really depends on how much laundry you do. A family of five running two or three loads a day needs it every year without question. A couple doing laundry twice a week can probably stretch to every two years. If you've got a long duct run, more than 15 feet, or multiple 90-degree elbows, lean toward annually. A rotary brush kit on an extension that spins off a drill does a great job. You can buy the kit for around $30 or just hire a pro for $80 to $150. Either way it's way cheaper than a new heating element.
Models Known to Experience FLOW-SENSE Errors
This repair applies to most Lg dryers with this error code. Common model numbers include: