Why Your Furnace Has a Strange Smell

As the weather turns cold and you switch from cooling to heating your home, some homeowners are worried about strange furnace smells floating in the air. Learn about what the most common furnace smells could suggest and how proactive you should be about each one. 

The Furnace Smells Musty 

Musty furnace smells usually imply mold growth hiding in the HVAC system. To avoid exposing your family to allergy-inducing mold, handle this problem right away. 

A wet air filter can encourage mold, so getting rid of the smell can be as simple as replacing the filter. If that doesn’t help, the AC evaporator coil placed near the furnace could be the culprit. This component accumulates condensation, which can trigger mold growth. You’ll be better off with a professional’s help to inspect and clean the evaporator coil. When all else fails, consider scheduling air duct cleaning. This service removes hidden mold, regardless of where it’s hiding in your ductwork. 

The Furnace Smells Like Spoiled Eggs 

This is one of the most concerning furnace smells due to the fact that it most likely implies a gas leak. The utility company includes 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 straightaway. If you remember where the main gas supply valve is located, shut that off too. Then, get out of the house and call 911, in addition to your gas company. Don’t enter the house until a professional tells you it’s safe. 

The Furnace Has a Sour Stench 

If you detect a sour smell that stings your nose while standing near64} the furnace, this may mean the heat exchanger is cracked. This important component contains68} combustion fumes, like carbon monoxide, so cracks may allow unsafe levels of CO gas into your home. 

Carbon monoxide poisoning could be deadly, so shut off your furnace immediately if you notice a sour odor. Then, contact an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is responsible. For your family’s safety going forward, see to it that you have reliable CO detectors on every floor of your home. 

The Furnace Smells Dusty 

When you start the furnace for the first time every fall, you should expect a dusty odor to show up 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 dissipates within one day, 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 up and out of your home. A smoky smell will sometimes mean the flue is clogged, and now fumes are settling back into your home. The odor may permeate the entire house, endangering your family’s health if you neglect it. So turn off the furnace and get in touch with a professional as soon as you can to schedule a repair. 

The Furnace Smells Like Burning Plastic 

Overheating and melting electrical components are the most common reason for a burning plastic smell to make an appearance. A failing fan motor is also possible. If you don’t tackle the problem, an electrical fire may start, or your furnace could suffer from irreparable damage. Shut off the heating system right away and contact an HVAC technician for help diagnosing and repairing this weird furnace smell. 

The Furnace Has an Oily Smell 

If you use an oil furnace, you might notice this odor if the oil filter becomes clogged. Try replacing it to find out if that addresses the problem. If the smell remains for more than 24 hours after completing this step, it might suggest an oil leak. You should get help from an HVAC specialist to handle this problem. 

The Furnace Reeks of Sewer Odors 

Sewer gas smells quite similar to rotten eggs, so first rule out the possibility of a natural gas leak. If that’s not the issue, the sewer lines may have an issue, for example a dry trap or sewer leak. Flush water down your own drains, including the basement floor drain, to refresh dried-up sewer traps. If the smell sticks around, you’ll need to contact a sewer line repair company. 

Contact Service Experts Heating, Air Conditioning & Plumbing for Furnace Repair 

If you’re still uncertain, get in touch with an HVAC technician to assess and repair your furnace. At Service Experts Heating, Air Conditioning & Plumbing, we offer thorough diagnostic services to identify the problem before the work begins. Then, we encourage 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 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 Service Experts Heating, Air Conditioning & Plumbing office today.