# How to Fix LG Error d90 (Airflow Blockage (90%))
The LG error code **d90** is a critical warning indicating that your dryer component is experiencing a severe restriction in its ventilation system. This means the hot, moist air cannot escape the unit, leading to extremely long drying times, overheating, and potential performance failures.
The “90” indicates that the machine is registering approximately 90% airflow blockage. This is often an issue that can be resolved without calling a technician.
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## 1. Explanation: What This Code Means in Plain English
The LG d90 code specifically alerts you to a **major airflow restriction** in your dryer’s exhaust system.
When the machine runs, it monitors the air pressure and temperature. If the air leaving the machine is hot but the pressure isn’t high enough—meaning the air isn’t moving fast enough—the system flags the obstruction.
**The most common causes for a d90 error are:**
1. A severely clogged or neglected lint filter.
2. A crushed, kinked, or disconnected flexible vent hose behind the machine.
3. Heavy lint or foreign object buildup in the permanent wall duct.
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## 2. Step-by-Step Fix: How to Diagnose the Airflow Blockage
Follow these steps sequentially, starting with the easiest checks first.
### Step 1: Safety & Initial Checks
**A. Unplug the Machine:** Before moving the appliance or inspecting internal components, **always unplug the unit** from the power source.
**B. Clean the Lint Filter:** Remove the lint filter (usually located inside the drum opening or at the bottom front of the machine). If you have a combo unit, ensure the secondary condenser/exhaust filter (if applicable) is also completely clear. Rinse the filter with water and a soft brush if necessary to remove invisible residue film, then dry thoroughly.
**C. Check the External Vent Hood:** Go outside to where the dryer vents terminate (usually a plastic hood or metal flap on the side of your house). Is the flap stuck closed? Is the opening completely covered in lint, spiderwebs, or even snow/ice? Clear any external debris.
### Step 2: Inspect the Flexible Ductwork (The Likely Culprit)
The flexible ductwork connects the back of your LG unit to the wall outlet. This is the single most common cause of high-percentage blockage errors.
1. **Carefully Pull the Machine Away:** Gently slide the washing machine away from the wall, allowing enough space to work behind it.
2. **Inspect the Vent Hose:** Examine the entire length of the silver or foil vent hose.
* **Is it crushed?** If the hose is pushed too close to the wall, it can flatten completely, causing 90% blockage. Gently reshape or adjust its position so it forms a wide, open loop.
* **Is it kinked or twisted?** Untwist the hose to ensure a straight path for air.
* **Is it disconnected?** Ensure the hose is securely clamped to both the back of the machine and the wall vent fitting. If it has fallen off, reattach and clamp it firmly.
### Step 3: Clear the Permanent Wall Duct
If the flexible hose is clear and properly installed, the blockage lies deeper within the permanent ductwork inside your wall.
1. **Remove the Hose from the Wall:** Disconnect the flexible hose from the wall outlet.
2. **Inspect the Wall Opening:** Shine a flashlight into the wall vent opening. Can you see large clumps of lint?
3. **Clean the Duct:** Use a specialized dryer vent cleaning brush kit (these brushes usually extend 10 to 20 feet) to snake down the permanent duct and push out lint accumulations.
4. **Confirm Airflow:** With the flexible hose still disconnected, temporarily turn on the dryer (if you can safely reach and plug it in for 10 seconds). You should feel a strong, consistent blast of air coming out of the wall opening.
### Step 4: Reassemble and Test
1. Reconnect the flexible ductwork securely to the wall outlet and the back of the machine.
2. Plug the unit back in and gently slide it into position, being careful not to crush the hose again.
3. Run a short, high-heat dry cycle (or a “Test Mode” if your manual provides one). The d90 error should now be cleared.
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## 3. Call to Action
If your flexible vent hose was damaged, ripped, or is made of the flimsy vinyl material (which is a fire hazard and prone to crushing), you should replace it immediately with a sturdy metal duct kit.
Check the price for a replacement Dryer Vent Kit here: https://www.amazon.com/s?k=LG+Dryer+Vent+Kit&tag=trivian-20
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