If you smell burning when your furnace kicks on or coming from the furnace itself, it’s likely there is a problem that needs to be addressed. Here are the most common causes of that alarming odor and how to address them. 

6 Reasons Your Furnace Smells Like Burning and How to Address Them

Dust and debris

One of the most common culprits behind a burning smell from your furnace is the accumulation of dust and debris within the unit. Over time, these particles settle in various components, including the burners and heat exchanger. When the furnace is turned on after a period of inactivity, these accumulated materials ignite, resulting in a temporary burning odor. The good news is that the smell should go away relatively quickly as the dust burns off. 

To prevent dust buildup, make sure your furnace is regularly serviced. Annual furnace maintenance performed by a certified HVAC technician can keep dust buildup from becoming a serious issue. During maintenance, your technician will thoroughly clean the various components, removing the accumulated dust and debris. This eliminates the potential for burning odors and also ensures your furnace operates efficiently and maintains good indoor air quality. 

Oil or gas leaks

If you own an oil or gas furnace and notice a burning odor resembling fuel, it’s critical to act swiftly and with extreme caution, as it may indicate a potentially hazardous issue: an oil or gas leak. 

With a gas furnace, a malfunctioning or irregular pilot light can be a sign of a gas leak. Check for a weak or flickering flame, which can indicate a problem. Gas leaks may also produce a faint hissing sound near the furnace, particularly around gas supply lines. 

If you smell and detect the smell of burning fuel, turn off the furnace immediately. It is a good idea to open windows to let the fumes escape your house. You should also avoid using any  open flame, such as lighters, candles or pilot lights on other appliances, because these could cause the fumes to ignite. If you suspect the leak is significant, leave your house, go to a safe location, and do not return until a professional technician confirms it’s safe to do so.

Once your furnace has been turned off and you have taken all the necessary safety precautions, contact a professional technician to diagnose and address the issue. Safety is paramount in this situation, so never overlook these potential risks.

Prevention is the best approach when it comes to oil and gas leaks. Ensure regular maintenance of your furnace and gas lines or oil tanks. Annual inspections by qualified technicians can identify potential issues before they become major concerns. Properly maintain your fuel storage tanks, and be vigilant for signs of deterioration or damage.

Dirty or clogged air filter

Your furnace’s air filter is responsible for capturing dust, dirt, and allergens in the air. Over time, however, the filter can become clogged and less effective at trapping these particles. A clogged air filter restricts the flow of air, leading to the overheating of your furnace. This overheating, in turn, generates a burning smell. 

By inspecting and replacing the air filter at regular intervals, you prevent the circulation of dusty air and promote better indoor air quality. In turn, this reduces the chances of dust and debris accumulating within the furnace, diminishing the likelihood of burning odors when the furnace starts up.

Electrical issues

Electrical problems in your furnace can emit a distinct acrid, burning smell. Recognizing the other signs of electrical trouble, such unusual sounds like buzzing or crackling and frequent short cycling, will help you determine whether an electrical problem is the cause of the smell. 

Professional assistance is a must when dealing with electrical problems in your furnace. Contact a qualified HVAC technician or electrician with expertise in furnace repairs. These professionals will inspect the wiring, connections, and electrical components, replacing any damaged parts or wiring to ensure the safe and reliable operation of your furnace. 

To prevent future electrical issues, maintain a clear space around your furnace to prevent dust buildup and avoid any DIY electrical repairs. 

Motor problems

Furnace components like the blower motor can experience malfunctions or overheating, which leads to a burning odor. This can sometimes be accompanied by unusual sounds like grinding or squealing. Reduced airflow and uneven heating are also telltale signs that your furnace’s motor is malfunctioning. 

When you suspect a problem with the motor, it’s a good idea to start by turning off your furnace to prevent any further damage. 

To resolve the problem, you should call a trained HVAC technician for help. The technician will examine the furnace’s blower motor, checking for issues such as worn-out bearings, lack of lubrication, or mechanical malfunctions. Depending on the diagnosis, the technician may replace damaged motor components or recommend replacing the motor entirely.

Mold or mildew

Moisture inside the furnace creates a conducive environment for mold or mildew growth. When the furnace heats up, these contaminants can emit a musty or burning odor. More than simply creating an unpleasant smell, burning mold and mildew can compromise your indoor air quality. 

To avoid this issue, address any sources of moisture or water leaks that may be contributing to the problem. You can prevent moisture buildup through proper insulation and ventilation around your furnace. Using a furnace humidifier can also help you maintain precision control over your home’s air moisture, ensuring it never becomes a breeding ground for mold or mildew. 

By maintaining control over the humidity within your furnace and your home, you’ll keep these unwanted and harmful odors away.

We Can Help with Burning Furnace Smells

Whether it’s something minor like dust or something major like a fuel leak, our professional HVAC technicians are ready to help find and fix whatever’s causing that smell. Contact us today to schedule an appointment.