What to Check First
- The fan noise may increase when the air purifier automatically circulates the air, but no message or indicator will appear on the display. This is normal.
- When the air purifier automatically circulates indoor air, the fan speed may suddenly increase, and you may notice an increase in noise. This is not a malfunction. It is normal operation caused by an automatic function designed to improve air circulation.
- In Auto mode, if the air quality remains clean (green or blue) for 50 minutes, the air purifier runs at a medium fan speed for 10 minutes to circulate the air. This is part of the air purifier’s automatic air circulation process. It helps detect hidden pollutants that have settled on the floor and keeps your indoor air clean.
- If the fan suddenly gets louder or the air quality indicator shows “Poor” even when dust level is low, follow the steps below.
- If the air purifier is automatically circulating the air, the fan noise may increase for about 10 minutes. After that, the fan speed will automatically adjust based on the current air quality. (Note: On Dual models, this may also occur during Single-mode operation.).
- If the dust level is low but the indicator stays red (“Poor”), the odor sensor may be detecting nearby odors. The overall air quality is based on the worse of the two readings: dust or odor. Check for items that may cause odors (such as cosmetics, perfumes, or scented candles) near the air purifier and move them away.
- Stale indoor air can trigger the sensor if the room has not been ventilated for a while. Open the windows to thoroughly ventilate the room, then check if the air quality returns to “Good (blue)”.
- This guide was created for all models, so the images or content may be different from your product.
Why This Can Happen
Symptoms can have more than one cause, and the correct steps depend on the exact model, installation and operating conditions. Use the checks above to narrow the issue before service.
Safety and Model-Specific Guidance
Stop troubleshooting if you notice burning, electrical damage, unsafe heat, gas odor, refrigerant concerns, or water near electrical components. Follow the official LG USA instructions for your exact model.
Frequently Asked Questions
What should I check first for Why does the LG air purifier suddenly get louder even when the indicator is blue (Good)??
The fan noise may increase when the air purifier automatically circulates the air, but no message or indicator will appear on the display. This is normal.
When should I stop troubleshooting and contact LG?
Stop if the product shows signs of electrical damage, burning, leaking near electrical components, or if the recommended checks do not resolve the issue. Use LG USA support for model-specific service guidance.
Does this guidance apply to every LG model?
Not always. Controls, error codes and service steps can differ by model. Confirm the exact model number and follow the linked LG USA article for model-specific instructions.