Dryer “Check Vent” Light & Blocked-Vent Codes by Brand (LG, Whirlpool, Samsung)
Sources checked: October 21, 2026. This guide summarizes the manufacturer and safety-agency pages linked at the end. CodeFix Home is independent of all appliance brands, and this guide has not been reviewed by a licensed appliance technician.
Quick answer
Many modern dryers measure airflow and warn you when the exhaust path is restricted: d75, d80, d90 or d95 on many LG dryers, AF or a “Check Vent” light on Whirlpool, and a check code at the end of Samsung’s vent blockage test on supported models. The dryer usually keeps running, but drying takes longer. Clean the lint screen first, then check the duct behind the dryer, then the outside vent hood. If the warning keeps returning, the duct inside the wall likely needs professional cleaning.
Safety first: unplug an electric dryer before moving it or touching the duct. If you have a gas dryer, do not disconnect or bend the gas line — leave moving a gas dryer to a professional. If you smell gas or burning, stop and get help. Safety disclaimer
Blocked-vent warnings by brand
| Brand | What you see | What the manufacturer says it means |
|---|---|---|
| LG | d75, d80, d90 or d95; bars on the Flow Sense indicator | The exhaust duct is restricted by roughly 75%, 80%, 90% or 95%. Two or four Flow Sense bars indicate a severe restriction. On gas models, d80 can also point to a lack of gas. |
| Whirlpool | AF or the “Check Vent” light | Restricted airflow detected at the start of an Automatic cycle. The dryer keeps running, but drying times get longer. |
| Samsung (DVE/DVG45B6300 and DVE/DVG50BG8300 series) | A check code at the end of the built-in vent blockage test | The duct system cannot exhaust properly and should be inspected and corrected. |
Codes vary by model. Always confirm in your owner’s manual — see how to find your model number.
Why airflow warnings matter
A restricted exhaust path keeps hot, humid air inside the dryer. Clothes take longer to dry, the dryer uses more energy and lint builds up in the duct. The U.S. Fire Administration notes that failing to clean the lint filter and dryer vents raises the risk of a dryer fire, so these warnings are worth acting on even when the dryer still seems to work.
Safe checks, in order
- Clean the lint screen. Remove lint before or after every load. If the screen looks clogged with residue, LG recommends washing it with warm water and a soft brush and letting it dry completely.
- Reduce the load size. Overloaded drums slow airflow. LG lists smaller loads as one of its first checks.
- Inspect the duct behind the dryer. Unplug an electric dryer and pull it out carefully. Look for a transition duct that is crushed, kinked, torn, loose at either end, or bunched up like a spring.
- Check the outside vent hood. With the dryer running, the flap should open fully. Remove any visible lint. Whirlpool suggests a simple test: after 5–10 minutes of running, the airflow under the hood should feel at least as strong as a hair dryer on high.
- Compare your vent run with the installation instructions. Too many elbows or too long a run can trigger the warning even when everything is clean. See dryer vent length limits.
- Run a normal heated cycle and see if the warning returns. Whirlpool notes its Check Vent light clears at the end of the cycle (or when you press Power or open the door) and comes back if the cause hasn’t been fixed.
Brand-specific notes
LG (d75, d80, d90, d95)
LG organizes its checklist by location: inside the dryer, behind it, outside the house and inside the walls. If the first three areas are clear, LG recommends hiring a dryer duct cleaner and asking for the total vent length and the number of 90-degree turns. Full details: LG dryer d80, d90, d95 codes.
Whirlpool (AF / Check Vent)
On models that have it, the Check Vent light appears only during Automatic cycles. Whirlpool’s steps are: clean the lint screen, check the duct for crushing or kinks, clear lint from the duct and outside hood, confirm the run length and number of elbows against the installation instructions, then run a Timed Dry cycle. If the message persists, Whirlpool recommends having the home’s venting cleaned by a specialist and offers a dryer vent test kit (part W11224254) through customer service.
Samsung (vent blockage test)
On the supported Samsung models, you can run the test yourself: make sure the dryer is cool (run Air Fluff for a few minutes if it’s warm), empty the drum, close the door, turn the dryer on and hold Adjust Time and Dryness together for about 3 seconds until “InS” appears, then hold Start/Pause. The test takes about 2 minutes. A “0” with a completion tone means the ducting is fine; a check code with an alarm means the duct system isn’t exhausting properly.
When to stop and call a professional
- The duct runs inside walls, ceilings or to a roof outlet that you can’t reach safely.
- The warning keeps returning after you’ve cleaned the lint screen, transition duct and outside hood.
- The duct is damaged, made of plastic or foil, or disconnected inside a wall.
- You have a gas dryer and the dryer would need to be moved.
- You notice a burning smell, scorch marks, or the dryer exterior gets unusually hot.
Related guides
- LG dryer d80, d90, d95: what to do next
- Dryer vent length limits: code vs. manufacturer manuals
- How to clean a dryer vent (and when not to)
- Dryer not heating: safe checks
Official sources
- LG US — Dryer error code list (checked Oct 21, 2026)
- Whirlpool — AF or “Check Vent” (Dryer) (checked Oct 21, 2026)
- Samsung US — Vent blockage test (checked Oct 21, 2026)
- U.S. Fire Administration — Clothes dryer fire safety
This guide is general information. Always follow your model’s owner’s manual and installation instructions. Featured image: illustration, not a photograph.
