Home furnaces are generally hidden away in a basement or utility closet so you may not be giving yours much thought. That is, of course, until they start to give off a strange smell. While some odours are completely normal, others are indications that there may be a problem with your furnace. Here are three of the most common causes of smells and what to do about them.
Burning Dust
One of the most common odors a furnace emits is that of burning dust. Particularly at the beginning of winter, this is nothing to be concerned about. That's because, when your furnace gets a break during the warmer months, dirt and dust can collect in the combustion chamber. When you turn your furnace on for the first time each season, all of that buildup is incinerated and blown throughout your home. The smell should dissipate in a matter of hours but, if it is bothering you, try to run your furnace during the day so you can open the windows and let the fumes escape. If the odor persists, it may be the sign of a larger issue best handled by a professional.
Dirty Air Filter
Air filters are an important part of forced-air home heating systems, gathering up all manner of allergens and other contaminants before they have the chance to enter your living space. A congested filter, however, can block air flow, trapping heat inside your furnace. That excess heat can damage or melt your system's components, giving off an odor of burning rubber or plastic. Poor air flow also forces your furnace's blower motor to work overtime. If the stress on the motor becomes too great, it will begin to overheat, producing a burning smell. To ensure optimum air quality and peak furnace function, be sure to replace your air filter every 30-60 days.
Worn or Damaged Parts
Over time, every mechanical device will succumb to wear and tear. Your furnace, regardless of its quality, is no exception. If you're experiencing a metallic smell, or one that reminds you of burning wires, odds are some part of your furnace is malfunctioning. While it can mean that a motor or heat exchanger needs to be replaced, these odors can also be a sign of faulty or worn electrical components. Electrical issues can not only damage your furnace, they can be a dangerous fire hazard. If you're smelling burning wires or metal, turn your unit off and call a HVAC technician right away.
