LG Dryer D90 Code – Causes & 10 Ways To Fix It 

Have you ever wondered why your LG dryer is taking too long to dry your clothes? Or worse, have you ever smelled smoke coming from your dryer? If you have, you might have encountered the LG D90 error code.

The D90 code means that 90% of the air that should be flowing out of your dryer is blocked somewhere in the venting system. 

But what if nothing is blocking your venting system? How do you fix it then? Not to worry, there are still several things you can try to make the D90 code go away with no blockage. The problem can sometimes be the dryer itself and not the exhaust system.

In this article, you’ll learn about the different causes of the LG Dryer code D90, how to fix it with 10 easy methods, and ways to prevent it from occurring in the future.

Causes of LG Dryer D90 Code

Many things that can cause the D90 code on LG dryers. Here are some of the most common ones:

Lint Buildup

A gradual accumulation of lint in the exhaust duct, lint filter, or external vent hood is one of the most common triggers of the D90 error.

As repeated drying cycles pass, dense lint buildup severely restricts airflow by 90% or more. This excessive blockage prompts the dryer sensors to display the D90 code.

Crushed or Damaged Exhaust Duct

If the flexible exhaust duct connected to the dryer’s rear vent is bent, kinked, or crushed in any way, it can significantly choke airflow by up to 90%.

The duct deformation limits ventilation, and that limitation can be detected by the dryer’s sensors.

Excessively Long or Winding Exhaust Duct

An excessively long, coiled, or winding exhaust duct with too many tight turns and bends can also trigger the D90 code by greatly restricting airflow. The extensive ductwork makes lint accumulation easier and hinders the dryer’s ability to receive enough air.

Clogging in the Wall or External Vent

clogged dryer vent cover

A clogged wall vent or external vent hood can trigger the D90 error code. These blockages restrict airflow, which dryer sensors detect as severely inadequate ventilation.

Lint and debris buildup at the back of the dryer itself over time can also cause restrictions that lead to D90 errors.

Small Load Size and Drying Time

Very small loads don’t provide enough internal airflow resistance for the dryer sensors to read accurately. The sensors can misinterpret the light load as a 90% restriction, triggering a false D90 code.

Additionally, excessively long drying times can indicate issues with airflow or other factors affecting the dryer’s efficiency.

Clogged Lint Filter

If the lint filter is extremely clogged with accumulated lint, it can choke airflow by over 90% past the filter. This airflow choking prompts the dryer sensors to display the D90 error code.

Faulty Thermostats

Defective high-limit or cycling thermostats unable to accurately monitor ventilation restrictions manifest as a D90 error even if no blockage exists. The faulty thermostats provide incorrect readings.

How to Fix LG Dryer D90 Code

If your LG dryer is displaying the frustrating D90 error, here are some troubleshooting steps you can take to resolve the problem:

1. Thoroughly Clean the Lint Filter

dryer lint filter

Ready to clean the lint filter? Start by removing the lint filter and brushing off debris using a soft brush.

While you are at it, also check the air exhaust where the lint filter is housed for ant blockages (buildup of lint). If any lint or debris is found, use a vacuum cleaner or brush to clean out the air exhaust.

For filters with heavy lint buildup, wash with water and detergent. After washing, rinse the filter thoroughly with running water and allow to dry before reinserting into the LG dryer.

2. Inspect the Exhaust Duct

First, unplug the dryer and disconnect the flexible exhaust hose from the back.

Look inside the duct and use a flashlight to inspect for lint buildup, especially around the ribs where lint gets trapped.

If you see any blockages, use a vacuum crevice tool to clear out the lint. Get into all the nooks and crannies.

Once it’s clean, securely reconnect the flexible hose.

Plug in and restart the dryer to see if the D90 error code has cleared.

3. Check Exterior and Wall Vents

Start by removing the outside vent cover and any vent grilles on your walls.

Shine a flashlight inside each vent and look closely for lint or debris clogging the airflow.

Use a vacuum hose and brush to thoroughly clean out any gunk inside the vents. Make sure to get into all the corners.

When done cleaning, firmly snap the vent covers back into place.

Double check the vents are completely clean before restarting your dryer. Proper ventilation is key!

dryer vent clog

4. Replace Faulty Thermostats

If you’re cycling or high-limit thermostats are defective, they can incorrectly detect airflow problems.

To replace them, first unplug the dryer and disconnect the thermostat wires.

Remove the mounting screws to detach the faulty thermostat.

Install a replacement thermostat recommended by the manufacturer. Reconnect the wires properly.

This should stop false readings that display the D90 error code.

5. Check the Power Supply and Circuit Breaker

What if you are experiencing there D90 error code because of your power supply or circuit breaker?

To cross that out of your checklist, check if your dryer is plugged into a 220-240V outlet. While checking that, also check for any damaged wiring.

Once all that is checked out, examine the circuit breaker to see if it has tripped. If you notice a tripped circuit breaker, reset it immediately.

Remember, consistent electrical power helps in preventing false readings that display the D90 error code.

If you think the problem is a faulty outlet or wiring after examination, hire an electrician to inspect and replace the faulty parts.

6. Increase Load Size

For very small loads, add a few extra items to increase to about 3/4 full drum capacity. This provides enough airflow resistance for accurate sensor readings.

Try to avoid overloading the dryer. Overloading the dryer will overload the motor.

7. Adjust or Replace Heating Element

If the air in the dryer drum is not heating up properly, the heating element may be defective.

Access the element by unplugging the dryer and removing the rear panel. Inspect the element and adjust/resecure if loose.

If burnt out, install a manufacturer-approved replacement with matching specs.

8. Adjust Flow Sense Setting

If it seems overly sensitive, check the owner’s manual on how to enter diagnostic mode and lower the “Flow Sense” setting. This prevents minor restrictions from erroneously triggering a D90 code.

Related Article: Flow Sense Overview

9. Check the Thermal Fuse

In some cases, a faulty thermal fuse can cause the LG Dryer D90 code to appear. The thermal fuse is a safety device that protects the dryer from overheating. If it becomes faulty or blows, it can disrupt the drying process and trigger error codes.

Use a multimeter to test the thermal fuse for continuity. If it is blown or defective, it will need to be replaced with a compatible thermal fuse to restore the dryer’s functionality and eliminate the D90 error code.

10. Professional Diagnosis and Repair

If you have tried all the above steps and still get the LG dryer D90 code but no blockage, you may need to contact LG support or a qualified technician for further diagnosis and repair.

There may be an underlying issue with the control board or other components that requires professional attention.

Preventing LG Dryer D90 Code

You can prevent the annoying D90 error code from appearing again in the future by implementing the following preventative maintenance measures:

Clean the lint filter after every cycle

Get into the habit of removing and cleaning the lint filter after each drying cycle.

Regular lint filter maintenance prevents gradual accumulation that can choke airflow.

Annual professional duct cleaning

Hire an HVAC technician once a year to thoroughly clean the entire length of the dryer ducting and external vent hood. They have specialized tools to clear lint in hard-to-reach areas. Professional cleaning prevents lint buildup over time.

Inspect ducting for damage

Periodically inspect the flexible exhaust duct for any crushing, kinking, or damage.

Straighten out any crushed sections and replace the duct if damaged. Deformed ducts severely restrict airflow.

bent dryer vent

Use smooth rigid metal ducts

When installing a new dryer, use smooth rigid metal ductwork rather than foil or flexible ribbed ducts.

Rigid metal ducts minimize lint accumulation and related airflow restrictions.

Limit ductwork length

Configure the exhaust duct pathway to be as short and straight as possible during installation. Follow the manufacturer’s recommended limits for optimal airflow.


The LG dryer D90 code is a serious issue that needs your attention.

The D90 code indicates that your dryer’s ventilation system is almost completely blocked by lint or other debris, which can cause many problems for your dryer and your home.

It can make your LG dryer inefficient, waste energy, and even start a fire.

To avoid these risks, you need to clean your dryer regularly and thoroughly. You need to wash the lint filter, and clear the exhaust hose, the wall duct, and the outside vent of any blockage.

You can also use the flow sense feature on your dryer to check the airflow and prevent the LG D90 error from happening again.

By doing these simple steps, you can fix the LG dryer D90 code and make your dryer work better and safer.

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