LG Washer Error Code d90

The d90 code on an LG washer-dryer indicates that the exhaust ductwork is approximately 90% blocked, severely limiting the dryer's ability to expel hot air. This is a near-critical airflow restriction that will cause poor drying performance and potential overheating if not addressed. The code is displayed for a 2-hour window and will clear from the screen on its own, but the physical blockage must still be found and corrected.

Yes, a 90% duct blockage is a serious condition that should be addressed promptly. Severely restricted exhaust airflow causes heat to build up inside the dryer, which can trip thermal safety components and shorten the life of internal parts. In extreme cases, lint accumulation in a hot, restricted duct can present a fire hazard. Do not continue using the dryer in a normal cycle until the obstruction has been cleared.

If the fix only requires cleaning lint from the existing duct and exterior vent cap, the cost can be minimal, typically in the range of $10 to $40 for a duct cleaning brush kit if you do the work yourself. Hiring a professional dryer vent cleaning service generally costs between $80 and $175 depending on the duct length and accessibility. If the flexible transition hose or a section of rigid duct needs to be replaced, parts and labor can add another $30 to $100 to the total.

Start by disconnecting the exhaust hose from the back of the unit and inspecting it along with the full duct run for lint buildup, kinks, crushing, or other obstructions. Check the exterior vent cap to confirm the flap opens freely and is not clogged. Clean the duct thoroughly using a dryer duct cleaning brush kit and replace any sections of hose that are kinked or damaged. Once the exhaust path is clear and unobstructed, run the dryer again to confirm normal operation.

The d90 code will clear from the display on its own after 2 hours, but resetting the unit or waiting for the code to disappear does not resolve the underlying blockage. If the exhaust restriction is not physically corrected, the appliance will continue to underperform and the code will return. Always address the ductwork issue before resuming dryer use.