Help Library: Help Library: Why does the LG air purifier suddenly get louder even when the indicator is blue (Good)?

Why does the LG air purifier suddenly get louder even when the indicator is blue (Good)?

Troubleshooting Air Purifier 05/22/2026

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<div class="content-service-view" itemtype="HowTo">
      <p class="description info-desc">
        When the air purifier automatically circulates indoor air, the fan speed
        may suddenly increase, and you may notice an increase in noise. <br/>
        This is not a malfunction. It is normal operation caused by an automatic
        function designed to improve air circulation.
      </p>
      
<h2 class="tit mainName">
        Why does the fan suddenly get louder when the indicator light show
        “Good” (blue)?
      </h2>
      <p>
        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. <br/>This is part of the air purifier’s automatic
        air circulation process. <br/>It helps detect hidden pollutants that
        have settled on the floor and keeps your indoor air clean.
      </p>      
<h2 class="tit">
        What to check if the fan gets louder or the indicator color does not
        match the actual air quality
      </h2>
      <p>
        If the fan suddenly gets louder or the air quality indicator shows
        “Poor” even when dust level is low, follow the steps below.
      </p>      
<div class="HowToStep">
        
<h3 class="name">Step 1. Wait and check the status</h3>
        <p class="text">
          If the air purifier is automatically circulating the air, the fan
          noise may increase for about 10 minutes. <br/>
          After that, the fan speed will automatically adjust based on the
          current air quality. <br/>(Note: On Dual models, this may also occur
          during Single-mode operation.)
        </p>      </div>
      
<div class="HowToStep">
        
<h3 class="name">Step 2. Check for odor sources nearby</h3>
        <p class="text">
          If the dust level is low but the indicator stays red (“Poor”), the
          odor sensor may be detecting nearby odors. <br/>
          The overall air quality is based on the worse of the two readings:
          dust or odor. <br/>
          Check for items that may cause odors (such as cosmetics, perfumes, or
          scented candles) near the air purifier and move them away.
        </p>      </div>
      
<div class="HowToStep">
        
<h3 class="name">Step 3. Ventilate the room</h3>
        <p class="text">
          Stale indoor air can trigger the sensor if the room has not been
          ventilated for a while. <br/>
          Open the windows to thoroughly ventilate the room, then check if the
          air quality returns to “Good (blue)”.
        </p>      </div>
      
<h3 class="warn-tit">Please note</h3>
      
<ul class="bul-list">
        
<li>
          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.
        </li>
      </ul>
      
<h2 class="tit">FAQ</h2>
      
<div class="qna-list">
        <dl>
          <dt class="name">
            
<span aria-label="Question">Q.</span> How is the overall air quality
            level displayed?
          </dt>
          <dd>
            
<span aria-label="Answer">A.</span> The air quality indicator shows
            four levels based on dust and odor (gas) levels: Good (blue) →
            Moderate (green) → Poor (orange) → Very Poor (red).
          </dd>
        </dl>
        <dl>
          <dt class="name">
            
<span aria-label="Question">Q.</span> Why is the indicator red even
            when the dust level is low?
          </dt>
          <dd>
            
<span aria-label="Answer">A.</span> Even if the dust level is low,
            the indicator will turn red if the sensor detects odors or gases in
            the room. Please ventilate the room.
          </dd>
        </dl>
      </div>

<p class="help-txt">
        This guide was created for all models, so the images or content may be
        different from your product.
      </p>    </div>

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Help Library

Why does the LG air purifier suddenly get louder even when the indicator is blue (Good)?

Why does the fan suddenly get louder when the indicator light show “Good” (blue)?

What to check if the fan gets louder or the indicator color does not match the actual air quality

Step 1. Wait and check the status

Step 2. Check for odor sources nearby

Step 3. Ventilate the room

Please note

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