If you detect new or unusual odors near your heating equipment, or wafting from the registers when the blower is running, it’s an understandable cause for concern. Here are some common heating system odors and their causes, as well as advice on what to do about the smells:
Sulfur or Rotten Egg Odors
If you notice a rotten egg smell near your gas furnace, it’s typically a warning sign of a fuel leak. Natural gas doesn’t have any odor, so a sulfur-based chemical, mercaptan, is added so hazardous leaks can be detected. If you suspect that you may have a gas leak, call your HVAC pro or your natural gas company right away, and for your safety, go outdoors until the leak is located and fixed.
Dirty Sock Smells
If your furnace starts to give off an unpleasant “dirty sock” odor, it’s likely due to bacteria that’s gained a foothold within the system. You can try replacing the air filter to see if that helps, but you may need to have the evaporator coil, blower assembly and ductwork professionally cleaned to eradicate the bacteria and eliminate the smell.
Burnt Metallic or Ozone-Like Odors
Overheating of the blower motor can create a distinctive burnt-metallic odor that smells similar to ozone or chlorine. When the motor isn’t functioning properly, it can easily overheat and cause the insulation to burn off the wiring. The sparks and shorts that accompany this kind of smell pose a fire hazard, so shut down your heating system at the breaker and call your HVAC contractor immediately.
Aroma of Warmed-Up Dust
When you fire up your furnace at the start of the heating season, you may notice an odor of heated dust when the blower fan cycles on. This odd but harmless smell is typically caused by a summer’s worth of dust buildup inside the heating system, and it’s a good reminder to replace the air filter and schedule a furnace maintenance visit with your HVAC technician.
For help determining the cause of heating system odors in your Indianapolis home, contact us at Mowery Heating, Cooling and Plumbing.
Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).