Why Your Furnace Has a Strange Smell

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

The Furnace Smells Musty

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

A clogged air filter can lead to mold, so eliminating the smell can be as easy as swapping out filter. If that doesn’t work, the AC evaporator coil placed near the furnace may be to blame. This component gathers condensation, which could stimulate mold growth. You'll be better off with a professional’s help to check and clean the evaporator coil. When all else fails, take a look at requesting air duct cleaning. This service cleans away hidden mold, no matter where it’s growing in your ductwork.

The Furnace Smells Like Spoiled Eggs

This is one of the most worrisome furnace smells because it most likely implies a gas leak. The utility company puts in a useful substance called mercaptan to the natural gas supply to make leaks easier to notice.

If you recognize a rotten egg smell around your furnace or originating from your air ducts, shut down the heater right away. If you can find where the main gas supply valve is located, shut that off also. Then, get out of the house and call 911, as well as 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 close to the furnace, this could mean the heat exchanger has cracked. This important component contains combustion fumes, like carbon monoxide, so a cracked heat exchanger could pump unsafe levels of CO gas into your home.

Carbon monoxide poisoning has the potential to be deadly, so turn off your furnace as soon as possible 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 responsible. For your family's safety going forward, see to it that you have functional CO detectors on every floor of your home.

The Furnace Smells Dusty

When you turn on the furnace for the first time after a while, you should expect a dusty odor to appear for a brief moment. 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 dissipates 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 clogged, and now fumes are flowing back into your home. The odor may permeate the entire house, jeopardizing your family’s health if you neglect it. So shut down the furnace and contact a professional straightaway to request furnace repair.

The Furnace Smells Like Burning Plastic

Overheating and melting electrical components are the most common reason for a burning plastic smell to appear. A malfunctioning fan motor is also possible. If you don’t address the problem, an electrical fire could start, or your furnace could suffer from irreparable damage. Disable the heating system immediately and contact an HVAC technician for help troubleshooting and repairing this unpleasant furnace smell.

The Furnace Has an Oily Smell

If you use an oil furnace, you may detect this smell when the oil filter becomes clogged. Try replacing it to find out if that fixes the problem. If the smell persists for more than one day after taking care of this step, it could indicate an oil leak. You should get help from an HVAC professional to address this problem.

The Furnace Smell Resembles Sewer Odors

Sewer gas smells very similar to spoiled eggs, so first eliminate the potential for a natural gas leak. If that’s not the source, your home's sewer lines may have an issue, such as a dry trap or sewer leak. Flush water down all your drains, including the basement floor drain, to replenish dry sewer traps. If the smell persists, go ahead and contact a sewer line repair company.

Contact Barlow Service Experts for Furnace Repair

If you're still unsure, get in touch with an HVAC technician to check and repair your furnace. At Barlow Service Experts, 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 resolve just about any heating malfunction, and we back our work with a 100% satisfaction guarantee for one year. To ask questions about why your furnace smells bad or to request furnace repair near you, please contact your local Barlow Service Experts office today.

chat now widget box