Why Your Furnace Has a Strange Smell

As the weather gets colder and you transition from cooling to heating your home, you might be worried about strange furnace smells floating in the air. Learn about what the most common furnace smells could mean and how proactive you should be about them. 

The Furnace Smells Musty 

Musty furnace odors usually indicate mold growth somewhere in the HVAC system. To avoid subjecting your family to mold and mildew spores, handle this problem right away. 

A damp air filter can lead to mold, so getting rid of the smell might be as simple as swapping out filter. If that fails to remove the smell, the AC evaporator coil mounted near the furnace could be the culprit. This component accumulates condensation, which could trigger mold growth. You’ll want a professional’s help to check and clean the evaporator coil. When the problem still won’t go away, consider scheduling air duct cleaning. This service cleans away hidden mold, no matter where it’s growing in your ventilation. 

The Furnace Smells Like Rotting Eggs 

This is one of the most nerve-wracking furnace smells since it most likely implies a gas leak. The utility company includes a special substance known as mercaptan to the natural gas supply to make leaks easier to notice. 

If you notice a rotten egg smell around your furnace or coming from your air ducts, switch off the heater straightaway. If you remember where the main gas supply valve is located, shut that off also. Then, evacuate your home and call 911, in addition to your gas company. Don’t reenter 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 close to64} the furnace, this might mean the heat exchanger has cracked. This vital component safely contains68} combustion fumes, like 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 lethal, so switch off your furnace right away if you recognize 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 working CO detectors on each floor of your home. 

The Furnace Smells Dusty 

When you start the furnace for the first time after a while, you should expect a dusty odor to fill the house for a few minutes. This is the smell of six months’ worth of dust burning up as the furnace wakes from its summer slumber. As long as the smell disperses within a 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 to the exterior. A smoky smell could mean the flue is blocked, and now fumes are backdrafting into your home. The odor may permeate the entire house, endangering your family’s health if you ignore it. So turn off the furnace and get in touch with a professional straightaway to arrange for repair. 

The Furnace Smell Resembles Burning Plastic 

Overheating and melted 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 tackle 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 diagnosing and repairing this weird furnace smell. 

The Furnace Has an Oily Smell 

If you have an oil furnace, you may pick up on this stench if the oil filter becomes blocked up. Try replacing it to find out if that fixes the problem. If the smell persists for more than 24 hours after completing this step, it might imply an oil leak. You should get help from an HVAC professional to handle this problem. 

The Furnace Smells Like Sewer Odors 

Sewer gas smells very similar to rotten eggs, so first rule out the potential for a natural gas leak. If that’s not the issue, the sewer lines might have an issue, for example 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 lingers, you’ll need to contact a sewer line repair company. 

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

If you’re still unsure, contact an HVAC technician to assess and repair your furnace. At Service Experts Heating, Air Conditioning & Plumbing, we perform thorough diagnostic services to pinpoint 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 resolve just about any heating repair, 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.