A burning smell from your furnace may be normal if you have not used the unit for some time. Mostly, it is just dust burning off. This odor quickly dies off after some time. However, a burning smell that continues as long as the furnace operates indicates an underlying issue. Homeowners should understand what causes this burning smell and know the necessary steps to solve the problem. This step is crucial to maintaining the safety and efficiency of the furnace. So, what are the primary causes of the burning smell?

1. Electrical Issues

The furnace has various electrical components, such as a blower motor, circuit boards, and wiring. They may have excessive resistance, which will lead to overheating. The overheated components produce a burning smell as the insulation on wires heats up. Short circuits can occur when an electrical circuit has an unintended connection between two points. This will result in a sudden surge in current flow, leading to overheating.

Overloading in the electrical system can also lead to excessive heat generation. This can happen if the furnace draws more current than designed or if other appliances share the same circuit. The burning smell may also occur when heated electrical components are in contact with combustible materials such as dust.

2. Dirty Air Filter

The filter cleans the air flowing into the furnace. When it is dirty, it may allow particles to flow into the system. They will then burn on the furnace components, creating a burning smell. Blocked air filters also restrict airflow. The furnace has to work harder to draw in air. This strain may cause the heating components to overheat. It will also lead to increased energy consumption.

You can prevent this problem by regularly cleaning or replacing the air filters. It can be done during the normal HVAC maintenance program, but most manufacturers recommend replacing the filters monthly. This will also ensure proper heating and improved indoor air quality.

3. Overheated Blower Motor

Dirty air vents and air filters will restrict airflow within the furnace. This limited air circulation may cause the blower motor to overheat, creating a burning smell. The furnace has safety mechanisms that will cause it to shut down when overheating.

If the system does not shut down, it may be due to a stuck limit switch. Cleaning and replacing the filters will allow free air movement. You may also check the vents to ensure they are open. An overheated blower motor can cause damage to other components. The heat exchanger can crack and allow carbon monoxide leakage into your home.

4. Burning Oil

Incomplete combustion in oil furnaces will result in the smell of burning oil. This mostly happens when there is an improper fuel-air ratio. It may be due to insufficient air or a malfunctioning burner. The burner nozzle sprays oil mist into the combustion chamber, mixing it with air and igniting it. If blocked, the atomization process is disrupted, leading to incomplete combustion. This results in the production of unburned vapors.

There may be oil leakage in the supply line or the fuel pump. The oil may come into contact with hot components and burn. Oil leaks pose a fire hazard and lead to inefficient furnace operation.

5. Dust and Debris

Periods of inactivity can allow dust and debris to settle on the internal components. When the furnace is turned on, the dust is exposed to high temperatures and burns off. This smell is distributed alongside heated air. Regular cleaning of the system and replacing filters will help prevent dust accumulation. You can also make sure your home is well-ventilated. Proper ventilation helps disperse odors and improve air quality.

Turn off the unit immediately when you notice a burning smell in your furnace. You may open the windows and doors to let in clean air and contact our HVAC experts. At OnTIME Service, we provide heating and cooling services in Henderson, KY and the Tri-state Area. You can count on us whether you need new HVAC system installation, tune-ups, or repair services to your existing systems. We are BBB accredited with an A+ rating. We also provide plumbing and air quality services around the clock. Contact OnTIME Service today, and we will help you with all aspects of HVAC services.

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