There are a few components of a furnace that are vital for its basic operations, and a couple particular kinds of sensors are often top examples here. Within gas furnaces specifically, the flame sensor is a basic sensor that plays some very important roles in terms of both operations and safety for your furnace – and it must be kept in good working order at all times.

At Lee’s Heating and Air, we’re here to offer comprehensive furnace services to clients around Salt Lake City, Provo, American Fork and nearby areas, including help with any distinct component. Here are some basics on what the furnace flame sensor is, why it’s a vital component for any furnace, and some possible signs that your flame sensor could be experiencing issues and require attention.

What Are Furnace Flame Sensors?

For those just learning about this term for the first time, the furnace flame sensor is a component that’s part of the safety system within your furnace. It’s designed to detect whether a flame is present when the furnace is running, and if so, prevent any gas from continuing to flow into the furnace – this protects against potential combustion or other hazards that could be dangerous for both you and your home.

Flame sensors are found in nearly all modern gas furnaces. They are a relatively simple component – a thin metal rod that’s placed within the flame itself, then extends back to the furnace control board. When it senses heat from the flame, it sends an electrical signal back to this board that tells it to keep the gas line open for continued operation.

Why Flame Sensor Issues Are Problematic

As we just noted, flame sensors are a key safety component for any furnace. If they aren’t functioning properly, the gas line may stay open even when there’s no flame present – this could lead to gas buildup and potential hazards.

In addition, if the sensor isn’t working correctly, it could also prevent your furnace from turning on at all. Therefore, keeping your flame sensor in good working order is essential for both safety and comfort.

Our next few sections will go over some of the possible signs that your flame sensor could be experiencing issues and may require attention from our professionals.

Rust or Other Corrosion Signs

Around the igniter area of your furnace, which is located near the burner, you might see signs of rust or other forms of corrosion. In some cases, this could actually be a sign that your flame sensor is no longer able to detect heat properly – it may not be able to send its signal back to the control board due to damage from these substances.

In other cases, the cause might be dirt or carbon buildup on the sensor itself. In either situation, replacing any components that have been damaged is usually the best solution. If rust is significant enough that it’s affecting performance, we may also recommend a full replacement of the furnace.

Constant Clicking Sound

Especially notable as your system is trying to turn on, a constant clicking sound could be an indication that your flame sensor has issues. In some cases, this may simply mean the sensor is dirty and needs cleaning – in others, it could be a sign of more serious damage or wear-and-tear to the component.

This often signals that the igniter is unable to light the burner because the system doesn’t recognize that there’s a flame within it. Cleaning or replacing the sensor is typically the solution here.

Yellow Flame Appearance

If you have a gas furnace, it should always be producing a blue flame. If the color is yellow or any other hue, this could be an indication that your flame sensor is malfunctioning. Yellow flames contain much more byproducts and impurities than blue flames, which means they’re less efficient and potentially even dangerous.

Poor Smells

Due to issues of exhaust that are not ventilating properly, a damaged flame sensor can occasionally also produce poor smells within your home. This is another sign that gas isn’t burning completely due to damage to the flame sensor – again, something that could be a danger.

At Lee’s Heating and Air, we’re here to help with HVAC services like furnace repair and maintenance if you’re noticing any of the above issues. Our professionals will assess your flame sensor and other potential causes to help you find the best solution for your home. Contact us today to learn more about our furnace services or schedule an appointment anywhere around SLC, Provo, American Fork or nearby areas.