How to Change Your Lennox Furnace Air Filter Quickly and Easily – 2024 Guide

A clean and properly functioning air filter keeps your Lennox Furnace running smoothly and efficiently, while also helping improve the air quality in your home. However, changing the air filter can be a task that some people find daunting or inconvenient, leading to a decrease in furnace performance and possible health problems.

In this blog post, we will guide you through the necessary steps, providing detailed instructions and tips to help you complete the task quickly, conveniently, and safely. So, let’s dive in and learn how to change your Lennox Furnace filter.

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1. Turn off the Furnace before Replacing the Air Filter


A basic rule in handling any electronic equipment is to make sure that it’s turned off. Once the furnace is turned off, locate the air filter and remove it carefully, taking note of the direction of the airflow indicated on the filter. By following this important step, you can help ensure a successful filter replacement and maintain optimal indoor air quality for your home.

2. Locate the Air Filter Compartment

A quick glance at the furnace’s manual will often indicate the air filter compartment’s location. In most cases, there will be a compartment door that you can easily slide or pull off to access the filter. Properly locating the air filter compartment is crucial for easy filter replacement and optimal furnace performance.

3. Take Out the Old Air Filter and Dispose of It Properly

Care should be taken when removing the old filter to avoid any injury such as cuts or punctures from sharp edges of the filter. Gently pull the filter out of its slot and place it into a plastic bag to prevent the spread of dust and debris. It is important to dispose of the old filter in the appropriate manner to prevent it from contaminating the environment.

4. Insert the New Air Filter with the Arrow Pointing Towards the Furnace


Take note of the direction of the airflow arrows, as you will need to match them with the new filter. Insert the new air filter with the arrow pointing towards the furnace, ensuring it is securely in place. Once the new filter is installed, turn the power supply back on and enjoy improved indoor air quality and furnace performance.

5. Turn the Furnace Back on and Check That the New Filter Is Securely in Place

Once in place, secure the filter cover or access panel back onto the furnace. Turn your furnace back on and monitor it for any irregularities in operation, such as strange noises or smells. Ensuring that your filter is correctly installed and the furnace is running smoothly will help to improve its energy efficiency and lifespan, ensuring optimal indoor air quality and comfort in your home throughout the cold months.

Maintaining Your Furnace for Optimal Performance and Efficiency


In addition to changing the air filter, it’s crucial to schedule regular professional maintenance. This typically includes cleaning the blower, inspecting the heat exchanger for cracks or signs of wear, checking the ignition system, and testing safety controls. Regular maintenance can help identify any potential issues early on and prevent costly repairs down the line.

Another important aspect of maintaining your Lennox furnace is to ensure proper ventilation. Keep the area around your furnace clear of debris, and make sure vents and registers are unobstructed. This will allow for better airflow and prevent any strain on the system.

By following these simple steps, you can keep your Lennox furnace running efficiently, providing you with reliable and comfortable heating for years to come.

6 Tips for Choosing the Right Air Filter for Improved Indoor Air Quality


1. Understand Your Needs

Before purchasing an air filter, consider the specific needs of your home or office. Factors to consider include the size of the space, the presence of pets or smokers, and whether any occupants suffer from allergies or asthma. Identifying your requirements will help you choose an air filter tailored to your situation.

2. Determine the Appropriate Filter Size

Air filters come in various sizes to fit different heating, ventilation, and air conditioning (HVAC) systems. Check your HVAC system’s owner’s manual or consult with a professional to determine the correct filter size for your system.

3. Consider the Minimum Efficiency Reporting Value (MERV) Rating

The MERV rating measures an air filter’s effectiveness in trapping particles. Ratings range from 1 (least efficient) to 20 (most efficient). Higher MERV-rated filters can capture smaller particles, but they may also restrict airflow, which can impact your HVAC system’s efficiency. Choose a filter with a MERV rating that balances filtration efficiency and system performance.

4. Look for HEPA Filters

High-Efficiency Particulate Air (HEPA) filters are the gold standard for air filtration. They can remove 99.97% of particles measuring 0.3 microns or larger, making them an excellent choice for people with allergies or asthma. However, HEPA filters can be more expensive and may require more frequent replacement.

5. Assess Filter Materials

Air filters are made from different materials, including fiberglass, pleated paper, electrostatic, and activated carbon. Fiberglass filters are the most affordable but least effective, while pleated paper and electrostatic filters offer improved filtration. Activated carbon filters are best for removing odors and volatile organic compounds (VOCs).

6. Consider Washable or Reusable Filters

Reusable filters can be cleaned and reused, making them a cost-effective and environmentally friendly option. However, they may not be as effective as disposable filters, and proper cleaning and maintenance are essential to ensure their efficiency.



In conclusion, changing the air filter in your Lennox furnace is a simple task that you can do on your own. It only takes a few minutes to complete and can greatly improve the air quality in your home, as well as your furnace’s overall performance. By following the steps outlined in this post, you can ensure that your furnace is running efficiently and that you and your family are breathing clean and healthy air. Remember to check and change your air filter regularly to keep your furnace in top condition.

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