LG dryer vent cleaning: what LG's own pages and manuals say
LG says a d75, d80, d90 or d95 code on its dryers means the exhaust duct is clogged 75%, 80%, 90% or 95%, and its troubleshooting page says this airflow warning is normally a sign to have a yearly vent cleaning done by a professional vent cleaner. LG's manual for its DL*X400 and DL*X408 dryers allows up to 65 feet of 4-inch rigid metal duct with no elbows, more than the 35 feet in the 2021 International Residential Code, which lets the dryer maker's instructions set the length instead. NFPA says to clean lint out of the vent pipe once a year, or more often if clothes take longer than normal to dry. This page quotes LG's own pages; it is not from LG.
LG dryer venting at a glance
| Item | What LG says | LG source |
|---|---|---|
| Vent cleaning | Have the home ventilation system cleaned by a professional vent cleaner once per year | Help Library, not heating or drying |
| Duct size and material | 4 inches in diameter; rigid, semi-rigid or flexible metal; no plastic or thin foil | DL*X400 owner's manual |
| Flexible metal duct | Total length must not exceed 8 ft. (2.4 m) | DL*X400 owner's manual |
| Maximum rigid duct, recommended wall cap | 65 ft. with no elbows, 28 ft. with four | DL*X400 owner's manual |
| Vent hood | Should have hinged dampers to prevent backdraft | DL*X400 owner's manual |
| Side or bottom venting | Adapter kit 383EEL9001B; right-side venting not available on gas models | DL*X400 owner's manual |
LG dryer vent cleaning: how often LG and NFPA say to do it
LG's page on a dryer that is not heating or drying lists, under maintenance, "Have the home ventilation system cleaned by a professional vent cleaner once per year." LG's DL*X400 manual says the interior of the appliance and exhaust duct should be cleaned periodically by qualified service personnel.
The National Fire Protection Association (NFPA) tip sheet gives the same interval: once a year, or more often if it is taking longer than normal for clothes to dry, clean lint out of the vent pipe or have a dryer lint removal service do it. NFPA also says the leading cause of home clothes dryer fires is failure to clean them.
LG Flow Sense and the d75, d80, d90 and d95 codes
LG's owner's manual describes Flow Sense as a sensing system that automatically detects blockages and restrictions in dryer ductwork. LG's error code list covers two forms of the warning: a code on the display, or bars on the Flow Sense indicator.
| What the dryer shows | What LG says it means |
|---|---|
| d75 | Exhaust duct clogged 75% |
| d80 | Exhaust duct clogged 80%; on gas dryers, d80 may indicate a lack of gas supplied to the unit |
| d90 | Exhaust duct clogged 90% |
| d95 | Exhaust duct clogged 95% |
| Two or four bars on the Flow Sense indicator | The exhaust system is severely restricted |
When the Flow Sense indicator shows four bars or lights up, the DL*X400 manual says to install a shorter or straighter run if the duct is too long or has too many turns, and to check and clean partly blocked ductwork immediately; the dryer can be used meanwhile, but drying will take longer and use more energy.
The manual's error table is stricter about the code itself. For the entry printed as "d8O, dGO, dGs" (exhaust system too long or with too many turns or restrictions), it says: "Do not use the appliance until the exhaust system has been cleaned and/or repaired." It also says to check that the outside vent has strong airflow while the dryer runs.
A Flow Sense indicator can stay on after the vent has been cleaned. The manual says the indicator stays on for 2 hours after a cycle in which it senses a restriction, and that after the restriction is cleared the system needs multiple consecutive cycles to see that performance has improved before the indicator resets. If it stays on for more than five cycles after the restriction has been cleared, LG says to call for service.
LG dryer Flow Sense test: the installation test
LG's manual says to run this test after installation to alert you to any serious problems in the home's exhaust system. These are the DL*X400 manual's steps:
- Start cool and empty. If the dryer warmed up, run Air Dry for a few minutes; remove the drying rack and literature, close the door, and load nothing (LG owner's manual).
- Start the test. Press and hold the Signal and Temp. buttons, then press Power. On glass touch panels, press Power, then immediately press and hold Signal and Temp. The code 1Ns shows if it worked (LG owner's manual).
- Press Start/Pause. The test lasts a few minutes; the heat turns on and drum temperatures are measured (LG owner's manual).
- Watch the Flow Sense light. If it has not turned on when the cycle ends, the exhaust system is adequate. If it turns on, the system is severely restricted: have it checked immediately (LG owner's manual).
LG cautions that even if the light does not come on, some restrictions may still be present. Button pairs vary by model: LG's not heating page lists Temp and Wrinkle Care for DLE7100 models, for example.
How to clean an LG dryer vent: LG's checks, in order
For the d80, d85, d90, d95 and Flow Sense result, LG's not heating page lists fixes to try before calling a vent specialist:
- Inside the dryer. Clean inside the dryer (LG not heating page). LG's lint filter steps are in the next section.
- Behind the dryer. Check that the exhaust hose is not crushed, dented, kinked or compressed, is completely straight or in an S curve, and has no holes or loose connections (LG not heating page).
- Outside the home. Start an Air Dry cycle, find the exhaust outlet, and verify the flappers open all the way. If they cannot open, replace the exhaust cover, and remove any visible lint around the exhaust (LG not heating page).
- Inside the walls. If those steps do not clear the code, LG says to contact a professional vent cleaning specialist and ask them to check lint accumulation, the length of the ventilation system from the dryer to the outside exhaust, the number of 90 degree angles, and any needed modifications (LG not heating page).
The general tools and method for the full run are in how to clean a dryer vent, and the checks other brands give for slow drying are in why a dryer is not drying.
LG dryer lint filter: how LG says to clean it
The DL*X400 manual says to clean the lint filter after every cycle: open the door, pull the filter straight up, and roll the lint off with your fingers or vacuum it. If it is very dirty or clogged with fabric softener, wash it in warm, soapy water and let it dry thoroughly before reinstalling. LG's error code list, in its section on airflow codes, says to remove lint from the lint tray between each load and to clean the tray with warm water and a soft brush, then allow it to dry before reinstalling. LG says never to operate the dryer without the lint filter in place.
Its troubleshooting table adds: hold the clean filter up to a light to see if it is clogged, and with high-lint loads such as new bath towels, it may be necessary to pause the cycle and clean it. LG's not heating page also says to clean the humidity sensor once per month, wiping each sensor bar 4 to 5 times with a damp cloth and letting it dry completely.
LG dryer venting: duct type and maximum length
The DL*X400 manual says to use only 4-inch rigid, semi-rigid or flexible metal ductwork, never plastic or thin foil, and that the total length of flexible metal duct must not exceed 8 ft. Non-rigid metal transition duct must be UL-listed. It says to keep the run as short as possible with as few elbows as possible, tape the joints instead of using screws that could catch lint, and insulate duct in unheated areas. LG says dryer failures caused by incorrect or inadequate exhaust systems are not covered by the dryer warranty.
| 90° elbows | Recommended wall cap | Cap for short runs only |
|---|---|---|
| 0 | 65 ft. (19.8 m) | 55 ft. (16.8 m) |
| 1 | 55 ft. (16.8 m) | 47 ft. (14.3 m) |
| 2 | 47 ft. (14.3 m) | 41 ft. (12.5 m) |
| 3 | 36 ft. (11.0 m) | 30 ft. (9.1 m) |
| 4 | 28 ft. (8.5 m) | 22 ft. (6.7 m) |
Under the chart, LG says to deduct 6 ft. for each additional elbow and not to use more than four 90° elbows. The manual also gives an airflow figure that can be measured: static pressure in the exhaust duct, read with a manometer about 2 ft. from the dryer while it runs with no load, should not exceed 0.6 inch. LG's own pages disagree on the hose behind the dryer: the not heating page says to verify it is rigid or semi rigid duct, while the error code list says to verify that whatever duct type you use ("Rigid, Semi-Rigid, or Flexible") is not crushed or kinked, and the manual allows flexible metal duct up to 8 ft.
LG's chart and the 35-foot code rule
LG's 65 feet and the code's 35 feet do not have to conflict: section M1502.4.6 of the 2021 International Residential Code says the maximum duct length is determined by one of three methods. Section M1502.4.6.1 sets a 35-foot maximum from the transition duct connection to the outlet, reduced for each fitting; a 4-inch radius mitered 90-degree elbow counts as 5 feet. Section M1502.4.6.2 lets the dryer manufacturer's installation instructions determine the size and maximum length instead, and says the code official shall be given a copy of those instructions at the concealment inspection.
| 90° elbows | LG chart, recommended cap | IRC 35 feet, with 4-inch radius mitered elbows (our arithmetic) |
|---|---|---|
| 0 | 65 ft. | 35 feet |
| 2 | 47 ft. | 25 feet of straight duct |
| 4 | 28 ft. | 15 feet of straight duct |
Where the 2021 IRC is adopted, a duct whose equivalent length exceeds 35 feet must carry a permanent label or tag stating that length, within 6 feet of the exhaust duct connection (M1502.4.7). LG's manual itself says venting must conform to local building codes. At the outside outlet, LG's error code list says it "may have flappers, a cage, or mesh to block animals or debris from entering"; LG does not tell readers to install a cage or mesh. The 2021 IRC says "Screens shall not be installed at the duct termination" (M1502.3). The elbow chart and worked examples are on how long a dryer vent can be.
LG dryer side vent kit
The DL*X400 manual says the dryer is configured to vent to the rear and can also vent to the bottom or side, using adapter kit part number 383EEL9001B from an LG retailer, which contains the duct parts to change the vent location. Right-side venting is not available on gas models. The manual's steps: remove the rear exhaust duct and the side knockout, press the adapter duct onto the blower housing, then push a taped 4" elbow and duct section, male end away from the dryer, through the side opening, leaving 1.5" protruding.
LG ventless and heat pump dryers
LG's product page for the DLHC1455W, a 24-inch, 4.2 cu. ft. compact dryer with Dual Inverter HeatPump technology, lists its vent type as Ventless and says it extracts moisture and recycles it. Its manual says warm air is expelled through the ventilation grille.
The maintenance is different. The DLHC1455 manual says to vacuum the cool air inlet grille 3 to 4 times a year so lint or dirt does not cause improper airflow. It uses a 2-piece lint filter: clean the inner filter before and after use, and the outer filter after drying 10 times or when lint builds up on it; a chime sounds after every 10 drying cycles.
If your LG dryer shows a Flow Sense alert or a d75, d80, d90 or d95 code after the checks above, a dryer vent cleaning company can check the run inside the walls. Use the form below and we will send your request to a company that serves your ZIP code.
LG dryer vent: common questions
How to fix Flow Sense on LG dryer?
Can my LG dryer be side vented?
How to take apart LG dryer to clean lint?
How to clean LG dryer lint filter with water?
Do LG dryers have two lint traps?
Sources
- LG, "LG Dryer: Error Code List": lg.com
- LG, "LG Dryer: Why is My Dryer Not Heating, Not Drying or Taking a Long Time Drying?": lg.com
- LG, Owner's Manual, DL*X400** / DL*X408** dryers, cover page: gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Venting the Dryer": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Routing and Connecting Ductwork": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Installing the Vent Kit": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Side Venting": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Checking Airflow": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Test Exhaust System": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Error Messages": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, troubleshooting, "Operation": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, "Cleaning the Lint Filter": gscs-manual.lge.com
- LG, Owner's Manual, DL*X400** / DL*X408**, warning statements, "Maintenance": gscs-manual.lge.com
- LG, DLHC1455W product page: lg.com
- LG, Owner's Manual, DLHC1455*, cover page: gscs-manual.lge.com
- LG, Owner's Manual, DLHC1455*, "Cleaning the Cool Air Inlet Grille": gscs-manual.lge.com
- LG, Owner's Manual, DLHC1455*, "Cleaning the Lint Filter": gscs-manual.lge.com
- International Code Council, 2021 International Residential Code, Chapter 15, section M1502 Clothes dryer exhaust: codes.iccsafe.org
- NFPA, "Clothes dryer safety" tip sheet: nfpa.org