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The Importance of a Functioning Furnace Flame Sensors

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As a homeowner, a properly functioning gas furnace creates a warm and comfortable environment. The furnace flame sensor is the furnace component that detects the presence of a flame and keeps the gas valve open. A bad flame sensor can impede the function of the entire combustion system, leading to higher gas bills and furnace issues. In the coming sections, get to know more about a properly functioning flame sensor, its role in your heating system, and how to maintain it for optimal performance.

What is a Flame Sensor?

A gas furnace flame sensor is a small, metal rod, safety device located near the burner assembly in your gas furnace. Its primary purpose is to detect the presence of yellow burner flames during the heating cycle. It signals the gas valve to open based on the presence of the yellow burner flames. The sensor is typically made of a heat-resistant metal, such as stainless steel or ceramic material, and might be covered in a porcelain casing. It is typically connected to the furnace’s control board, behind the access cover.

How does a Flame Sensor Work?

Understanding the mechanics of a flame sensor will give you a clear picture on how this piece fits into a well-functioning furnace. When your furnace receives a call for heat, the ignition system creates a spark or heats up the surface to ignite the gas. As the flame appears, the flame sensor detects its presence by ionizing the air around it. The sensor then sends a signal to the control board, confirming that the burner is lit and functioning correctly. If the sensor does not detect a flame, it will shut off the gas supply as a safety precaution to prevent the accumulation of unburned gas.

The Importance and Benefits of a Functioning Sensor

A properly functioning flame sensor is important to maintain your heating system’s safety, efficiency, and longevity. By promptly addressing issues with your flame sensor, you can avoid more significant problems that may require costly repairs or a complete furnace replacement. Let’s explore the key benefits of a functioning flame sensor and the consequences of a malfunctioning one:

  • In the event the sensor does not detect yellow burner flames, the sensor will quickly shut off the gas supply, preventing the buildup of unburned gas in your home.
  • Preventing the accumulation of built-up gas will avoid potential gas leaks, explosions, or carbon monoxide poisoning.
  • A malfunctioning flame sensor could either fail to detect a flame, leading to a gas leak or incorrectly sense a flame, causing the furnace to continue supplying gas even when there is no fire.
  • If the sensor malfunctions, it may cause your furnace to short cycle, meaning it will turn on and off frequently without completing a full heating cycle.
  • A malfunctioning flame sensor can put unnecessary strain on your combustion system, leading to reduced efficiency, higher gas bills, and increased wear and tear.

Sensor Failure and Replacement

Over time, your flame sensor may become dirty or corroded, impacting its ability to detect a flame accurately. If you notice some of these common symptoms, have a professional gas technician inspect your furnace and conduct a flame sensor replacement if it is necessary. Some signs that your flame sensor may need to be replaced include:

  • The furnace continuously turns on and off without finishing a heating cycle, also called short cycling.
  • The furnace fails to ignite or stay lit.
  • The furnace shuts off shortly after ignition.
  • The burner flame appears weak or inconsistent.

Testing a New Sensor

After a flame sensor replacement, your gas technician should test the new sensor to confirm its proper functionality. This involves monitoring the furnace during a heating cycle to verify that the sensor accurately detects the presence of a flame and communicates with the control board. A thorough test will give you peace of mind knowing that your new sensor works correctly and your furnace operates safely.

Cleaning and Maintenance

Maintaining your gas furnace flame sensor will keep your combustion system working and reduce the need for flame sensor replacement. Regular cleaning and inspection by a professional gas technician can help prevent issues.

  • During your annual furnace tune-up, your HVAC technician will inspect the sensor for any signs of damage or corrosion and clean it if necessary.
  • Cleaning the sensor involves gently removing any dirt, dust, or debris that may have accumulated on its surface.
  • Cleaning the flame sensor can be done using fine-grit sandpaper or an abrasive cloth.
  • In some cases, your technician may recommend replacing the sensor if it shows significant wear or damage.

A functioning flame sensor is essential for the safety and longevity of your heating system. By understanding its role, recognizing the signs of a failing sensor, and prioritizing regular maintenance, you can have a furnace that operates at its best while keeping your home and family safe. If you suspect a malfunctioning flame sensor or issues with your furnace, always consult with a licensed HVAC professional to diagnose and resolve the problem.

The Logan Difference

Logan A/C & Heat is a family-owned and operated business that puts our customers first. Our commitment to excellence begins with our rigorous training program, which keeps our installers up-to-date on the latest industry standards and best practices. We understand that a new HVAC system is a significant investment for our customers, which is why we have all the necessary parts supplied before starting any project, minimizing delays and frustration for our clients.

Our team takes the time to walk through the entire installation process with our customers, explaining each step and answering any questions. Once the installation is complete, we thoroughly demonstrate how to operate and troubleshoot the new system, ensuring that our customers feel confident and comfortable with their investment.

When you choose Logan A/C & Heat, you can trust that you are working with a team that truly cares about your comfort, safety, and satisfaction. Experience the Logan Difference for yourself and discover why we are the preferred choice for HVAC services in our community.

Frequently Asked Questions

How often should I replace my flame sensor?

The lifespan of a flame sensor can vary depending on factors such as the brand, model, and usage of your furnace. On average, flame sensors last between 3 to 5 years. Have your furnace regularly maintained and inspected to determine if a flame sensor replacement is needed.

Can I clean my flame sensor myself?

While it is possible to clean your flame sensor yourself, having a professional HVAC technician handle this task is generally recommended. Improperly cleaning the sensor or damaging it in the process can lead to further issues with your furnace. A professional can also identify any other potential problems with your heating system during the maintenance process.

What causes a gas furnace flame sensor failure?

Several factors can contribute to sensor failure. Dirt, dust, and debris accumulation on the sensor’s surface can hinder its ability to detect the presence of a flame accurately. Exposure to moisture or chemicals can lead to corrosion, which may cause the sensor to malfunction. Physical damage, such as cracks or breaks, can also compromise the sensor’s performance. Lastly, normal wear and tear can cause the sensor to degrade and eventually fail. Regular maintenance and cleaning can help prevent many of these issues and extend the life of your flame sensor.

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