As the weather gets colder and you transition from cooling to heating your home, some homeowners are worried about unusual furnace smells floating in the air. Learn what the most common furnace smells mean and how proactive you should be about each one.
The Furnace Smells Musty
Musty furnace odors generally suggest mold growth somewhere in the HVAC system. To avoid exposing your family to these microorganisms, handle this problem right away.
A clogged air filter can encourage mold, so eliminating the smell can be as straightforward as swapping out filter. If that doesn’t work, the AC evaporator coil fastened near the furnace might be the culprit. This component collects condensation, which will sometimes trigger mold growth. You'll be better off with a professional’s help to examine and clean the evaporator coil. When the problem still won't go away, consider investing in air duct cleaning. This service eliminates hidden mold, no matter where it’s growing in your air ducts.
The Furnace Smells Like Spoiled Eggs
This is one of the most concerning furnace smells since it frequently implies a gas leak. The utility company adds a special substance known as mercaptan to the natural gas supply to make leaks easier to detect.
If you notice a rotten egg smell near your furnace or originating from your vents, switch off the heater immediately. If you remember where the main gas supply valve is, shut that off as well. Then, evacuate your home and contact 911, as well as your gas company. Don’t enter the house until a professional confirms 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 has cracked. This important component safely contains combustion fumes, such as carbon monoxide, so a cracked heat exchanger may allow unsafe levels of CO gas into your home.
Carbon monoxide poisoning has the potential to be fatal, so shut off your furnace as soon as possible if you notice a sour odor. Then, reach out to an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is the culprit. For your health and safety going forward, make sure you have functional CO detectors on each floor of your home.
The Furnace Smells Dusty
When you turn on the furnace for the first time each fall, you probably expect a dusty odor to appear for a little while. This is the smell of six months’ worth of dust burning away as the furnace wakes from its summer slumber. As long as the smell disperses within 24 hours, you don't have anything to worry about.
The Furnace Has a Smoky Smell
Natural gas, oil and propane furnaces are combustion appliances, so they vent fumes to the exterior. A smoky smell will sometimes mean the flue is blocked, and now fumes are settling back into your home. The odor might eventually reach the entire house, jeopardizing your family’s health if you neglect it. So switch off the furnace and call a professional straightaway to schedule a repair.
The Furnace Smells Like Burning Plastic
Overheating and melted electrical components are the most common reason for a burning plastic smell to appear. A faulty fan motor is another common cause. If you don’t address the problem, an electrical fire might start, or your furnace could experience irreparable damage. Shut off the heating system immediately and contact an HVAC technician for help diagnosing 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 blocked up. Try replacing it to see if that resolves the problem. If the smell persists for more than one day after completing this step, it could suggest an oil leak. You'll be better off with help from an HVAC specialist to address this problem.
The Furnace Smells Like Sewer Odors
Sewer gas smells very similar to spoiled eggs, so first eliminate the possibility of a natural gas leak. If that’s not the problem, your home's sewer lines could have an issue, such as a dry trap or sewer leak. Try pouring water down your own drains, including the basement floor drain, to replenish dried-up sewer traps. If the smell sticks around, go ahead and contact a sewer line repair company.
Contact Air Engineers Service Experts for Furnace Repair
When in doubt, contact an HVAC technician to assess and repair your furnace. At Air Engineers Service Experts, we perform comprehensive diagnostic services to pinpoint the problem before we figure out the best solution. Then, we encourage the most viable, cost-effective repairs, as well as an up-front estimate for all options. Our ACE-certified technicians can resolve just about any heating problem, and we back our work with a 100% satisfaction guarantee for one year. To learn more about why your furnace smells bad or to request furnace repair near you, please contact your local Air Engineers Service Experts office today.