Furnace Smells like Burning

Furnace smells can come from a variety of sources, the most common being dust.  Just as dust can easily accumulate on shelves inside homes, dust will settle on dormant parts of the HVAC system. The usual burning odor marks the first time the heater is turned on for the season. This is simply due to burning dust off that has settled on furnace’s internal components such as:

  • Burners
  • Ducts 
  • The heat exchanger
  • The ignition system

This type of smell should only stick around for an hour or two. If you sense that it is still lingering in the air, try checking your HVAC air filter. Dirty or clogged air filters can add to the burning odor and even trap the odor molecules within itself. 

Another way to remove the offending smell is to freshen up the air inside your home. Cracking windows and opening up doors will certainly help do the trick. However unless you do so before a cold spell settles in, it will be uncomfortable to say the least. This is where air purifiers or cleaners can step in to assist. Not only can air purification remove bad odors, it can also eliminate:

  • Dust
  • Chemicals
  • Bacteria and viruses
  • Airborne soot from fireplaces and candles
  • Mold spores created from higher indoor heat and humidity levels

At Satterlee, we offer air purifiers such as Lennox Pure Air or IWaveR to support better indoor air quality for homes and businesses. You can prevent many negative health side effects simply by improving the air quality. While bacteria and viruses can be easily brought into your home, air purifiers eradicate these problems.

Furnace Smells like Burning Plastic or Electrical Odors

Persistent burning odors are warning signs that can be dangerous or costly if not handled quickly. Beyond dusty or clogged air filters, any burning odors that don’t disappear after a few hours is signaling a problem. On top of being unable to remove debris from the HVAC system, dirty air filters also restrict airflow. Restricted airflow then leads to overheated HVAC parts such as a blower motor. Furthermore, the filter can also trap odor molecules from the dust burning from the furnace parts. This can also lead to a lingering-more-than-normal odor.

Another reason why internal furnace parts can overheat is due to blockage in the air return ducts. The system needs an intake of cold outside air to keep the combustion process running properly. Without the cold air, the furnace will overheat and trigger the shutdown safety precautions. Furthermore, if safety components like the heat exchanger continually overheat, they can break down. This can allow deadly carbon monoxide into your home. Signs of an cracked and worn down heat exchanger can be:

  • Soot on / inside the furnace
  • Yellow burner flame, instead of blue
  • A chemical odor
  • Moisture near your furnace

A burning odor can also signal that a foreign object has fallen into the heating system. This is especially true if you can detect a stronger odor coming from a particular vent. Things from plastic utensils or a bottle cap to a child’s toy can easily slip into the vents unnoticed. As burning plastic creates toxic fumes, always shut off your furnace as soon as possible. 

Electrical wires that lose their protective insulation not only produce a burning odor, it’s also a very serious fire hazard. Immediate diagnostics and repair is needed to inspect and replace all damaged wiring. 

Furnace Smells like Rotten Eggs / Sulfur Odor 

Carbon monoxide is incredibly dangerous as it is invisible and scentless. To help early detection from homeowners, a sulfuric odor is artificially added. If you ever catch a whiff of a sour-like odor, shut down the furnace and gas line immediately. This could be a potential gas leak in your system due to a cracked or failing part.  

How You can use Furnace Preventative Maintenance to Avoid that Furnace Burning Smell 

If you notice any unusual or persistent odors, immediately shut down your furnace. The first area(s) to check is the filters. If the filter is clean then immediately call for an HVAC technician as a deeper issue is occurring. You can also visually search for burn damage or smoke cautiously without touching any potentially overheated parts. Costly repairs like a overheated blower motor or a cracked heat exchanger are preventable with regular maintenance like:

  • Changing filters
  • Cleaning air return duct and furnace vents
  • Fixing faulty wires 

All these smaller issues and more can easily be caught and fixed before further damage is done with regular maintenance. It’s recommended to have an annual maintenance schedule for your furnace, especially to catch any gas leaks. In addition to catching early-stage problems, HVAC technicians will clean off the furnace to help prevent start-of-the-season heater odors. Just keep in mind that most modern furnaces have a lifespan of 15-20 years. As the furnace ages and needs more and more repairs, it’s advised to start calculating a replacement cost. You are more likely to save money by getting a replacement unit if any repairs cost over 20% of a new unit.

Annual Furnace Maintenance Service with Satterlee

Regardless of the smell coming from your furnace, they all pose a serious health and safety risk to your family. If your furnace is persistently producing any type of smell, you will need HVAC technicians to investigate the source. At Satterlee, our HVAC professionals are constantly training to safely diagnose, remove the source of the smell, and repair your furnace. Don’t hesitate to call us today if you notice any persistent odors! Or if you wish to prevent unwanted odors, let us help you with your annual furnace maintenance! 

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