Why Your Furnace Has a Strange Smell

As the weather gets colder and you switch from cooling to heating your home, you might be worried about unusual furnace smells filling the air. Find out what the most common furnace smells could mean and how worried you should be about them.

The Furnace Smells Musty

Musty furnace smells almost always suggest mold growth hiding in the HVAC system. To avoid subjecting your family to these microorganisms, handle this problem right away.

A clogged air filter can encourage mold, so getting rid of the smell could be as easy as getting a new filter. If that fails to remove the smell, the AC evaporator coil fastened near the furnace might be the root of the problem. This component accumulates condensation, which can induce mold growth. You'll want a professional’s help to examine and clean the evaporator coil. When all else fails, start thinking about investing in air duct cleaning. This service cleans away hidden mold, regardless of where it's hiding in your ductwork.

The Furnace Smells Like Rotten Eggs

This is one of the most worrisome furnace smells due to the fact that it frequently indicates 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 detect a rotten egg smell close to your furnace or coming from your air ducts, shut off the heater straightaway. If you know where the main gas supply valve is placed, shut that off too. Then, evacuate your home and dial 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 might mean the heat exchanger has cracked. This vital component houses combustion fumes, like carbon monoxide, so a cracked heat exchanger may spew unsafe levels of CO gas into your home.

Carbon monoxide poisoning has the potential to be deadly, so turn off your furnace right away if you notice 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 continued safety going forward, make sure you have functional CO detectors on every floor of your home.

The Furnace Smells Dusty

When you fire up the furnace for the first time every fall, you should expect a dusty odor to fill the house 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 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 safely out of your home. A smoky smell could mean the flue is clogged, and now fumes are settling back into your home. The odor can reach through the entire house, jeopardizing your family’s health if you ignore it. So shut down the furnace and get in touch with a professional as soon as you can to arrange for repair.

The Furnace Smells Like It's Burning Plastic

Overheating and burned electrical components are the most plausible reason for a burning plastic smell to come from your furnace. A failing fan motor is another common cause. If you don’t correct the problem, an electrical fire could start, or your furnace could suffer from irreparable damage. Disable the heating system as soon as possible and contact an HVAC technician for help diagnosing and repairing this unpleasant furnace smell.

The Furnace Has an Oily Smell

If you have an oil furnace, you might notice this stench if the oil filter becomes blocked up. Try replacing it to determine if that addresses the problem. If the smell remains for more than a day after taking care of this step, it might imply an oil leak. You'll be better off with help from an HVAC professional to fix this problem.

The Furnace Reeks of Sewer Odors

Sewer gas smells pretty similar to spoiled eggs, so first rule out the potential for a natural gas leak. If that’s not the problem, your home's sewer lines could have an issue, like a dry trap or sewer leak. Try pouring water down the drains, including the basement floor drain, to refresh dry sewer traps. If the smell persists, go ahead and contact a sewer line repair company.

Contact TML Service Experts for Furnace Repair

If you're still uncertain, contact an HVAC technician to check and repair your furnace. At TML Service Experts, we offer complete diagnostic services to identify the problem before we figure out the best solution. Then, we recommend the most viable, cost-effective repairs, alongside an up-front estimate for every option. Our ACE-certified technicians can resolve 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 TML Service Experts office today.

chat now widget box