Why Your Furnace Has a Strange Smell
As the weather cools down and you swap from cooling to heating your home, some homeowners are worried about unusual furnace smells floating in the air. Find out what the most common furnace smells could mean and how concerned you should be about each one.
The Furnace Smells Musty
Musty furnace odors generally indicate mold growth hiding in the HVAC system. To avoid subjecting your family to allergy-inducing mold, address this problem as soon as possible.
A wet air filter can harbor mold, so eliminating the smell can be as easy as swapping out filter. If that doesn’t work, the AC evaporator coil fastened near the furnace might be the culprit. This component accumulates condensation, which can stimulate 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 removes hidden mold, regardless of where it's hiding in your ventilation.
The Furnace Smells Like Rotten Eggs
This is one of the most nerve-wracking furnace smells because it most likely suggests a gas leak. The utility company puts in a special substance known as mercaptan to the natural gas supply to make leaks easier to detect.
If you detect a rotten egg smell around your furnace or originating from your vents, shut off the heater straightaway. If you know where the main gas supply valve is located, shut that off too. Then, evacuate your home and contact 911, followed by your gas company. Don’t enter 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 may mean the heat exchanger cracked open. This vital component contains combustion fumes, like carbon monoxide, so cracks might allow unsafe levels of CO gas into your home.
Carbon monoxide poisoning could be lethal, so turn off your furnace as soon as possible if you recognize a sour odor. Then, call an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is the culprit. For your family's safety going forward, ensure you have working CO detectors on all floors of your home.
The Furnace Smells Dusty
When you fire up the furnace for the first time every fall, you probably expect a dusty odor to appear for a few minutes. This is the smell of six months’ worth of dust burning off as the furnace wakes up. As long as the smell goes away within one day, you shouldn'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 safely out of your home. A smoky smell will sometimes mean the flue is backed up, and now fumes are backdrafting into your home. The odor can reach through the entire house, endangering your family’s health if you neglect it. So turn off the furnace and call a professional as soon as you can to request furnace repair.
The Furnace Smells Like It's Burning Plastic
Overheating and melting electrical components are the most likely reason for a burning plastic smell to come from your furnace. A faulty fan motor is another common cause. If you don’t correct the problem, an electrical fire could start, or your furnace could end up with irreparable damage. Disable the heating system right away and contact an HVAC technician for help identifying and repairing this weird furnace smell.
The Furnace Has an Oily Smell
If you use an oil furnace, you may notice this smell if the oil filter becomes clogged. Try replacing it to see if that resolves the problem. If the smell lingers for more than a day after carrying out this step, it could imply an oil leak. You'll be better off with help from an HVAC expert to fix this problem.
The Furnace Reeks of 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 issue, the sewer lines could have an issue, like a dry trap or sewer leak. Flush water down your own drains, including the basement floor drain, to fill dried-out sewer traps. If the smell sticks around, go ahead and contact a sewer line repair company.
Contact Service Experts Heating & Air Conditioning for Furnace Repair
If you're still unsure, call an HVAC technician to examine and repair your furnace. At Service Experts Heating & Air Conditioning, we deliver thorough diagnostic services to determine the problem before repairs begin. Then, we suggest the most viable, cost-effective repairs, as well as an up-front estimate for all options. Our ACE-certified technicians can handle just about any heating repair, and we back our work with a 100% satisfaction guarantee for one year. For details about why your furnace smells bad or to request furnace repair near you, please contact your local Service Experts Heating & Air Conditioning office today.