Having a working flame sensor is critical for a functioning furnace. While most furnaces last for 10 to 20 years, flame sensors have a much shorter lifespan of about five years. Usually, when a flame sensor goes bad, the best route is to replace it outright.

What Is a Flame Sensor?

A flame sensor is a small device in your furnace that makes sure that a flame is burning while the furnace is running. If the flame goes out, unburned gas can escape and fill the air with dangerous levels of carbon monoxide. Using its small electrical current, the flame sensor’s job is to shut the furnace off entirely if it stops detecting a flame. Here are some signs that your flame sensor is no longer working.

The Sensor Is Corroded or Covered in Rust

Since the flame sensor is on the front side of a low-power electric circuit, it can experience the same issues as other electric circuits. It’s worthwhile to check your flame sensor now and then to look for corrosion or rust. If you can’t see the sensor or aren’t sure where it’s located, a heating professional from Queen City Heating & Cooling can help.

The Porcelain at the End of Your Sensor Is Cracked

If your flame sensor’s porcelain is cracked, it’s best to call an HVAC professional to get it checked out and likely replaced.

The Furnace Shuts Down Immediately Upon Being Powered on

If your furnace shuts off within just a few seconds of being turned on, the issue is probably the flame sensor. If you think the flame sensor is still in working condition, there could be a deeper problem within the furnace itself.

Furnace Repair

Water Leaks

Water leaking around your furnace is a clear sign of a serious problem. If you also have an AC unit in the home and aren’t sure what’s really causing the leak, do your best to get a general idea of where it’s coming from as this will help your HVAC tech solve the problem. If you think it might be coming from the furnace, get in touch with an HVAC professional as soon as possible.

Your Furnace’s Burner Flames Are Yellow

A flame sensor that is in working order should burn away the gas entirely, resulting in blue-colored flames. If the flames are yellow in any area, something isn’t right.

Since yellow flames are generally caused by excess carbon monoxide, check the reading on your home’s carbon monoxide detector to make sure it isn’t too high. Sometimes, a technician can improve the issue by performing a gas burner cleaning.

You’re Constantly Adjusting the Thermostat

A furnace’s inability to adjust when the air gets too hot is often caused by an issue with the flame sensor. If you find yourself frequently adjusting the thermostat to get enough cool air running through your home, it’s worth looking into.

Your Utility Bills Are Higher Than Normal

Another sign of a bad flame sensor is a high utility bill. If you’re sure that your air filters are clean, your flame sensor could be causing the furnace to struggle. Even if there aren’t any visible signs of damage to the sensor or furnace, something deeper could be happening.

While replacing your furnace’s flame sensor is usually your best option in dire situations, routine heating maintenance from the experts at Queen City Heating & Cooling can prevent issues before they arise. Sometimes, it can even temporarily fix problems or increase your flame sensor’s lifespan.

Cleaning the Sensor

Since your flame sensor is frequently exposed to fire and smoke, soot buildup is inevitable over time. However, cleaning your sensor is a quick and easy process that can make all the difference.

To locate the flame sensor, you’ll typically need to remove the furnace’s cover. The flame sensor is made of metal and should be located just outside the burner. There’s likely a porcelain cover around its end to prevent contact with the metal. It’s never a bad idea to check the furnace’s manual if you’re unsure of the flame sensor’s location.

If the flame sensor looks dirty or damaged, give us a call, and we’ll send a technician over to take a look. If the flame sensor looks clean and new yet your furnace is still struggling, a technician from Queen City Heating & Cooling will be happy to diagnose the problem.

At Queen City Heating & Cooling, we’re here to serve homes in Springfield, Missouri and the surrounding areas. In addition to furnace repairs, we offer services like AC installation and AC repair, indoor air quality, water heating, emergency repair, and more. Our team of professionals is passionate about giving you and your loved ones the most comfortable living experience possible.

Give us a call today!

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