A furnace generates heat, either using gas burners or electrical heating elements, to warm up the air, then uses a blower to send the heated air into the ductwork of a home. As with any heat-generating appliance, there’s some potential for a fire hazard, although this is rare for modern furnaces. However, if you ever notice an acrid burning odor coming from the vents when your home’s furnace is running, it can be alarming.
Is there reason to be concerned? On some occasions, yes. If you don’t know why it’s happening, please shut off the furnace and call an HVAC professional for furnace repair in Shreveport, LA. Trying to investigate furnace troubles or doing repairs yourself may lead to safety hazards.
Below, we list some of the reasons why you may notice burning odors from your furnace and what to do about it.
Dust burning off the heat exchanger
Burning odors are common when a furnace first comes on after a long period of inactivity. This is something you probably already experienced back in the fall when you turned on the furnace for the first time in months. The odor is dust burning off the heat exchanger (gas furnaces) or heating elements (electric furnaces). It will soon go away.
Electrical wiring trouble
This can occur with both electric and gas furnaces. The modern gas furnace uses multiple electrical components to run, like the blower fan motor and the electronic ignition system. In fact, the most likely source of an electrical burning smell is the blower motor burning out. This is something you’ll want a professional looking into as soon as possible. The motor will probably need to be replaced. There are other wires in the furnace that may be burning due to loss of insulation and the current passing through the wrong parts of the system. All these need an expert to examine them. Don’t risk a high voltage shock.
Clogged filter
The furnace filter can create numerous problems if it is allowed to become clogged, and we urge all furnace owners to replace the furnace every 1 to 3 months. If the lint and other debris caught in the filter becomes too hot, it can give off a distinct burning odor—a warning you need to change the filter out right away!
Something in the furnace that shouldn’t be there
We’ve done a lot of work on furnaces over the years, so we can tell you some strange object can find their way into them. Small plastic items inside the furnace can create a noticeable plastic burning smell. If the smell continues, you may have a problem with wire insulation burning off, which can lead to more serious problems with the furnace.
Burning circuit board
This is arguably the most serious problem that can stem from a burning odor. Loss of the circuit board will shut off the furnace, and it’s expensive to have the circuit board replaced. The burning odor may have a “gunpowder” smell, and this is definitely a reason to shut off the furnace and call for help.
Need to solve a furnace problem? Call the Doctor of Home Comfort—Hall’s Heating, Air Conditioning & Refrigeration.
