How To Reset The Filter Light On Filtrete Air Purifiers

Filtrete air purifiers display red lights to indicate clogged filters. After cleaning or replacing the filter, you need to reset the red light to turn it off and use the air purifier.  

The same reset process applies to all Filtrete air purifiers. After replacing the filter, connect the unit to a 120V power source and switch it on. Then press the “Filter Change Indicator” button for three seconds (or until the light turns off).  

If you use any model of Filtrete air purifiers, read this article to learn how to reset them. The post also discusses how Filtrete air purifiers work, what filters they have, and how to replace and clean them. You will also find some interesting FAQ on the topic.

How Do Filtrete Air Purifiers Work?

The general working mechanism of Filtrete units is similar to other air purifiers. They draw air inside the system and circulate it through filtration to remove airborne particles and pathogens. The clean air is then emitted out of the appliance.  

All Filtrete air purifiers use a high-grade True HEPA filter (conforming to the DOE standard) with an efficiency of 99.97%. It removes microscopic airborne pollutants, dust, debris, smoke, bacteria, molds, etc., that measure 0.3 microns or more. When the HEPA filter becomes saturated, the device notifies you by displaying a solid red filter light

Apart from the True HEPA filters, Filtrete air purifiers also have a pre-filter. But it does not play a significant role in filtration and can be reused after cleaning.  

When To Reset The Filter Light on Filtrete Air Purifiers

The filter light on Filtrete air purifiers must be reset every time it illuminates. There are two main reasons why your Filtrete air purifier light might be on: 

1. Clogged Filter

Filtrete air purifiers have a highly efficient filtration system that traps the maximum amount of contaminants from the air. This filter has a specific capacity, beyond which, it cannot capture more pollutants. Once the filter becomes saturated, it is indicated by the Filter Change Indicator

The indicator monitors filter use and signals when it needs replacement. Its light turns solid orange when the filter has 10% remaining life and a solid red when the filter expires.

The filter life varies with usage and type of pollutants.  

Daily Hours Of OperationAverage Filter Life
6 hours12 months
12 hours6 months
24 hours3 months

Depending on environmental conditions, the filter may require more frequent replacement. Extremely poor air quality (severe pollution) or excessive exposure to fire, tobacco smoke, construction material, etc., can affect the filter media causing it to swell and saturate quickly. 

All of this combined, means filters should be regularly checked for clogs or saturation.  

Cleaning filters can prolong their life. Although True HEPA filters cannot usually be reused, you can clean them with a vacuum cleaner to remove some of the dust and debris and prolong their lifespan. However, under no circumstances rinse it, as water can damage the filter media. 

2. Improper Filter Installation

After replacing the filter, if the red light doesn’t turn off, check if your filter is inserted correctly and secured in position. If the filter feels too tight or too loose, it is either not the right size, or some obstruction prevents it from fitting correctly.

Unusual noise from the air purifier and no air purification usually confirm this is the problem.  

Clean the air purifier to remove the blockage, in particular inside the filter housing.

Compare the model number on your filter with the one on your air purifier (mentioned on a label at the bottom of the appliance), and make sure the filter is compatible with your unit. Also, remove any packaging materials before installing the filter, and it should fit correctly.

Plentiful Air also has a complete troubleshooting guide if you find that your air purifier is not only displaying a red light, but is also not working available here.

How To Reset Filtrete Air Purifiers

The reset process is the same for all Filtrete air purifiers. The units do not come with an exclusive reset icon; instead, the Filter Change Indicator (also labeled as a Reset icon) can be used to reset the filter light. 

Resetting the Filter Light

  • After replacing the filter, plug it into a 120V AC power outlet, and turn the air purifier on. 
  • Locate the Filter Change Indicator and press it for approximately three seconds. 
  • Wait for the light to turn off. 
  • This completes the reset process.  

Note that these steps only reset the filter light, and you will need to set the controls: 

Fan Speed

Filtrete air purifiers have a fan at the entrance of the unit to draw air inside. This fan also rotates to circulate the air through the system. The fan speed determines the rate of filtration, and a high speed naturally fastens the process.   

Filtrete allows you to select the fan speed. The fan can operate on any one of the three built-in speed levels, and you can press the “FAN” icon to cycle through the given options. 


The timer function enables you to set a specific operating time for the air purifier, after which the unit automatically shuts off. Press the “TIMER” button on the control panel until it displays the desired time limit. 

Lighting Function

The lighting function on Filtrete air purifiers turns all the display lights off, and you can enable the option to turn bright lights off while sleeping. Pressing the “Light” icon on the control pad once turns the display off for 12 hours. 

Filter Reset Button locations on Filtrete Air Purifiers

Filtrete air purifiers have a “Filter Change Indicator” that can be used to reset the filter light. The control panel can be found at the top side of all Filtrete units (in front of the air outlet). Here’s how it is arranged from left to right: 

  • A power button should be pressed once to turn the unit on or off. 
  • Fan Speed button with three display lights for each speed level.  
  • Timer button with three display lights for 2, 4, and 8 hours each. 
  • Filter Change Indicator (reset button)  
  • Light button  


How Do You Change a Filter On a Filtrete Air Purifier?

To change the HEPA filter on a Filtrete air purifier, remove the filter cover on the front of the unit, hold the HEPA filter from the sides, gently push it down and then pull it out. Place the filter cover by inserting its two bottom knobs into the slots on the device and push it to lock.  

The smart technology on Filtrete air purifiers notifies you whenever the True HEPA filter needs changing. Make sure to order your replacement filter when the Filter Indicator turns orange (10% remaining filter life). The filter should be purchased by matching the unit’s model and the series number.  

Make sure to turn the unit off and disconnect it from the electrical source before replacing the filter. Also, ensure to reset the filter lightly to use the air purifier again. 

Filtrete air purifiers also have a pre-filter to trap large-sized dust and debris and protect the device. It is a generic filter, and the Filter Change Indicator doesn’t light up when it becomes saturated.  

If the pre-filter becomes saturated, it obstructs the airflow and heats up the unit. These filters are not supposed to be replaced regularly and can be reused after dusting and cleaning with lukewarm water every few weeks. 

Filtrete’s complete range of filter replacements for air purifiers is available on

What Does Pre Mean On a Filtrete Air Purifier?

Pre-filters are filters with a large pore size that trap dust and debris. Instead of True HEPA filters that actually purify the air, pre-filters only remove large airborne particles to prevent them from getting stuck in the system. 

Unlike True HEPA air filters, the pre-filters can be cleaned and reused.  

How To Clean a Filtrete Air Purifier?

To clean a Filtrete air purifier, turn it off and disconnect it from the power source. Clean the exterior of the unit with a damp, clean cloth, and use a dry brush for the grills and the fan. Rinse the pre-filter and let it dry before placing it back.  

Here’s how to clean a Filtrete air purifier: 

  • Turn the filter off and disconnect it from the power source. 
  • Use a soft, dirt-free, damp cloth to clean the outside of the unit. 
  • Locate the air inlet and outlet grills, and clean them with a small, dry brush. 
  • Avoid using water or detergents, soaps, bleach, or volatile cleaning agents inside the unit. 
  • Remove the pre-filter, dust it with a dry cloth and then rinse it with lukewarm water. 
  • Let the pre-filter dry before installing it back. 
  • If the air purifier makes noise during operation, or overheats, move the fan manually and check for any blockage. Use a dry brush to remove it and clean the fan.  
  • Although cleaning the True HEPA filter doesn’t do much, you can vacuum the filter to prolong its life. 

Theresa Orr

Theresa Orr is an Earth Scientist who specializes in determining past climates from rocks using geochemistry. Her passion for clean water, soil and air drives her to provide easy to understand information for everyone to read.

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