Common Reasons Your Heater Smells Funny

As the temperatures outside start to drop, you know it’s time to switch on the heater. But when you do, you immediately smell something like burning coming from your furnace. You wonder to yourself, “Why does my heater smell like burning plastic when I turn it on?” You start to worry that perhaps something is wrong with your furnace. Is it going to catch on fire? Is it going to fill your home with smoke?

Relax. In most cases, that burning smell coming from your furnace is nothing to worry about. In this post, we’ll explain the most common reasons and one not so common reason, why heaters smell weird when they’re first turned on for the season—and how we fix the problem so you can enjoy a warm home all winter long.

We recommend that you have your furnace maintenance done annually AND by a professional certified technician. As always, SS&B Heating & Cooling is here to help you make sure your heater is ready for the Missouri winter.

Debris on a Gas Furnace's Burner Assembly

Another reason your gas furnace might emit a burning smell is the presence of debris in its burner assembly—the part where combustion takes place. Over time, dust, dirt, and other debris can accumulate in this area, potentially hindering proper combustion when your heater starts up again after being off all summer. When combustion doesn't occur as it should, it can result in a burning odor. Here are the steps we take to clean your gas furnace's burner assembly:

Turn off power to the furnace at both the thermostat and the disconnect switch or circuit breaker panel before performing any work on the HVAC system.
Remove any necessary panels to access the burners.
Use a vacuum with a soft brush attachment or compressed air to remove any debris from around the burners.
Once everything is clean, reassemble all the components.
Finally, turn on the power to the heater at both your thermostat and the disconnect switch or circuit breaker panel.

Debris on an Electric Furnace's Heating Element

Another reason your electric furnace might emit a burning smell is the presence of debris on its heating elements—the components responsible for generating heat in an electric furnace. Over time, dust and other particles can accumulate on these elements, which may affect their performance when your heater starts up again after being off all summer. When the heating elements don't function optimally, it can result in a burning odor. Here are the steps we take to clean your electric furnace's heating element:

Turn off power to the furnace at both the thermostat and the disconnect switch or circuit breaker panel before performing any maintenance on the HVAC system.
Remove any necessary panels to access the heating elements.
Use a vacuum with a soft brush attachment to carefully remove any debris from around the heating elements. If needed, repeat the cleaning process until all dust is removed.
Once everything is clean, reassemble all the components.
Finally, turn on the power to the electric furnace at both your thermostat and the disconnect switch or circuit breaker panel.

One not so common reason… is the smell of rotten eggs!

The reason you're noticing a strong, egg-like smell coming from your furnace is because of the chemicals that have been added to let people know there's gas leaking. If this happens and it resembles what we describe as "rotten eggs" then don't wait another minute before calling for our help! This could result in fires or even explosions if not dealt with quickly enough by professionals who understand how dangerous these leaks can be. If you notice this odor coming from your heater, turn off the system immediately and call us for assistance!

A burning smell coming from your furnace when you first turn it on for the season is normal in most cases—especially if it smells like plastic. More often than not, this is caused by dust buildup on heating elements or debris in burner assemblies. These problems are not too complicated to fix. If you have any questions or concerns about why your heater smells funny when you turn it on, don't hesitate to reach out to us today, we'll be happy to help. In fact, our furnace maintenance service will go through all these checks and more!

Maintaining a Clean HVAC Filter for Winter Comfort

Keeping your HVAC filter clean during the winter months is crucial for maintaining a warm and healthy home. As your heating system works harder to keep you comfortable in the colder weather, the filter plays a vital role in ensuring its efficiency. A clean filter allows for proper airflow, which is essential for even heating and optimal energy performance. Moreover, it helps trap airborne particles like dust, allergens, and pollutants, preventing them from circulating through your home and improving indoor air quality. Regularly checking and changing or cleaning your HVAC filter, typically every one to three months, depending on usage and filter type, ensures that your heating system operates smoothly, saves energy, and provides you with the cozy warmth you need throughout the winter season.