Understanding Furnace Flame Sensors - Wisler Plumbing, Heating, Cooling, & Electrical

In the HVAC systems space, furnace flame sensors play a critical role in ensuring the safety and efficiency of heating processes. These small but important components are responsible for detecting the presence of a flame in the furnace, thus maintaining a stable and controlled combustion process. In this blog post, we’ll take a deeper look at how furnace flame sensors work, when to consider repairs, and some basic knowledge to keep your heating system in top shape.

How Do Furnace Flame Sensors Work

Furnace flame sensors are generally thin metal rods, often made of stainless steel, positioned in the flame path of the burner. Their main function is to monitor the presence of a flame during the combustion process. The sensor works with the furnace’s ignition system, which creates a spark or ignites a pilot light to light the main burner.

The flame sensor is connected to the furnace control board or gas valve circuit. When the burner ignites, the flame sensor produces a small electrical current. This current is then sent back to the control board, signaling the presence of a flame. When the sensor does not detect a flame, the control board cuts off the gas supply to prevent the release of unburned gasses into the environment, ensuring safety.

Common Issues and When to have Flame Sensor Repair

Like any other component of an HVAC system, furnace flame sensors can develop problems over time. The most common problems include:

It’s important to fix these problems quickly to keep your furnace running reliably. Signs that your flame sensor may need attention include frequent burner cycles, difficulty maintaining a stable flame, or the furnace shutting off unexpectedly.

If you are experiencing any of these furnace flame sensor issues, call the experts at Wisler! They are proficient in many furnace solutions and serve many areas, including HVAC repairs in Roanoke.

Basic Maintenance Tips

To keep your furnace flame sensor in optimal condition, consider the following maintenance tips:

Regular Cleaning

Clean the flame sensor regularly with fine emery cloth or steel wool to remove accumulated carbon and dirt. Make sure the furnace is turned off before you begin cleaning.

Visual Inspection 

Check the sensor for signs of oxidation or corrosion. If you notice any, gently clean the affected areas and apply a thin layer of high-temperature antioxidant paste if necessary.

Secure Electrical Connections 

Inspect the wiring connecting the flame sensor to the control board for signs of wear or damage. Tighten any loose connections and replace any damaged cables.

To avoid further problems with your furnace, it’s worth enrolling in the Diamond Club Family Member! With this membership a “Proper maintenance always costs less than repair.”, and If you’re a member and have your system checked by Wisler every 6-months, our Complete Comfort Guarantee GUARANTEEs no breakdowns all season or we come back and fix it for FREE. optimizations to ensure your system is ready for anything! Call Wisler today or visit their website for more information.

Furnace flame sensors are unsung heroes in the HVAC world, quietly ensuring our heating systems are safe and efficient. Understanding how they work, identifying common problems, and performing regular maintenance can go a long way toward preventing breakdowns and costly repairs. If you are experiencing ongoing problems or are unsure about the condition of your furnace’s flame sensor, it is advisable to consult a professional HVAC technician to continue ensuring the comfort and safety of your home.