As the weather gets colder and you swap from cooling to heating your home, you might be worried about unusual furnace smells floating in the air. Learn about what the most common furnace smells could mean and how proactive you should be about each one.
The Furnace Smells Musty
Musty furnace odors almost always indicate mold growth someplace in the HVAC system. To avoid exposing your family to mold and mildew spores, address this problem right away.
A clogged air filter can encourage mold, so getting rid of the smell might be as simple as getting a new filter. If that doesn’t work, the AC evaporator coil placed near the furnace might be the culprit. This component collects condensation, which can stimulate mold growth. You'll want a professional’s help to examine and clean the evaporator coil. When the problem still won't go away, consider requesting air duct cleaning. This service eliminates hidden mold, no matter where it's hiding in your air ducts.
The Furnace Smells Like Spoiled Eggs
This is one of the most worrisome furnace smells because it most likely indicates a gas leak. The utility company adds a useful substance known as mercaptan to the natural gas supply to make leaks easier to notice.
If you recognize a rotten egg smell near your furnace or coming from your ductwork, switch off the heater immediately. If you know where the main gas supply valve is placed, shut that off too. Then, evacuate your home and call 911, as well as your gas company. Don’t reenter the house until a professional tells you it’s safe.
The Furnace Has a Sour Stench
If you discover a sour smell that stings your nose while standing near the furnace, this could mean the heat exchanger cracked open. This vital component contains combustion fumes, like carbon monoxide, so a cracked heat exchanger may spew unsafe levels of CO gas into your home.
Carbon monoxide poisoning could be deadly, so shut off your furnace immediately if you detect a sour odor. Then, call an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is responsible. For your continued safety going forward, make sure you have reliable CO detectors on each floor of your home.
The Furnace Smells Dusty
When you fire up the furnace for the first time each fall, you should expect a dusty odor to appear for a little while. This is the smell of six months’ worth of dust burning off as the furnace wakes from its summer slumber. As long as the smell disperses within 24 hours, you have nothing to worry about.
The Furnace Has a Smoky Smell
Natural gas, oil and propane furnaces are combustion appliances, so they vent fumes safely out of your home. A smoky smell can mean the flue is blocked, and now fumes are settling back into your home. The odor can reach through the entire house, risking your family’s health if you ignore it. So turn off the furnace and contact a professional right away to schedule a repair.
The Furnace Smells Like It's Burning Plastic
Overheating and burned electrical components are the most likely reason for a burning plastic smell to come from your furnace. A faulty fan motor is also possible. If you don’t correct the problem, an electrical fire may start, or your furnace could experience irreparable damage. Turn off the heating system right away and contact an HVAC technician for help troubleshooting and repairing this unusual furnace smell.
The Furnace Has an Oily Smell
If you own an oil furnace, you might pick up on this stench if the oil filter becomes clogged. Try replacing it to see if that fixes the problem. If the smell remains for more than 24 hours after carrying out this step, it could imply an oil leak. You should get help from an HVAC expert to handle this problem.
The Furnace Smells Like Sewer Odors
Sewer gas smells quite similar to rotting eggs, so first eliminate the potential for a natural gas leak. If that’s not the source, your home's sewer lines could have an issue, such as a dry trap or sewer leak. Flush water down all your drains, including the basement floor drain, to refresh dried-up sewer traps. If the smell persists, go ahead and contact a sewer line repair company.
Contact Service Experts Heating & Air Conditioning for Furnace Repair
If you're still unsure, get in touch with an HVAC technician to assess and repair your furnace. At Service Experts Heating & Air Conditioning, we perform complete diagnostic services to identify the problem before repairs begin. Then, we recommend the most viable, cost-effective repairs, along with an up-front estimate for each option. Our ACE-certified technicians can manage just about any heating malfunction, and we back our work with a 100% satisfaction guarantee for one year. To ask questions about why your furnace smells bad or to request furnace repair near you, please contact your local Service Experts Heating & Air Conditioning office today.