Why Your Furnace Has a Strange Smell

As the weather cools down and you transition from cooling to heating your home, you may be worried about unusual furnace smells filling the air. Learn what the most common furnace smells mean and how proactive you should be about each one. 

The Furnace Smells Musty 

Musty furnace odors usually suggest mold growth somewhere in the HVAC system. To avoid exposing your family to mold and mildew spores, handle this problem as quickly as possible. 

A wet air filter can harbor mold, so eliminating the smell can be as easy as swapping out filter. If that fails to remove the smell, the AC evaporator coil fastened near the furnace might be the culprit. This component collects condensation, which can induce mold growth. You’ll be better off with a professional’s help to check and clean the evaporator coil. When all else fails, consider investing in air duct cleaning. This service removes hidden mold, regardless of where it’s hiding in your ventilation. 

The Furnace Smells Like Rotting Eggs 

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

If you notice a rotten egg smell near your furnace or coming from your ductwork, switch off the heater immediately. If you know where the main gas supply valve is located, shut that off too. Then, leave the house and contact 911, in addition to your gas company. Don’t go back in the house until a professional can verify it’s safe. 

The Furnace Has a Sour Stench 

If you discover a sour smell that stings your nose while standing near64} the furnace, this could mean the heat exchanger is cracked. This vital component houses68} combustion fumes, including carbon monoxide, so a cracked heat exchanger could spew unsafe levels of CO gas into your home. 

Carbon monoxide poisoning has the potential to be lethal, so shut off your furnace immediately if you recognize a sour odor. Then, call an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is to blame. For your family’s safety going forward, ensure you have working CO detectors on every floor of your home. 

The Furnace Smells Dusty 

When you start the furnace for the first time after a while, you can expect a dusty odor to fill the house for a brief moment. This is the smell of six months’ worth of dust burning up as the furnace wakes up. As long as the smell disperses 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 up and 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 may permeate the entire house, endangering your family’s health if you ignore it. So switch off the furnace and contact a professional right away to request furnace 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 make an appearance. A malfunctioning fan motor is also possible. If you don’t address the problem, an electrical fire may start, or your furnace could suffer from irreparable damage. Turn off the heating system right away and contact an HVAC technician for help troubleshooting and repairing this weird furnace smell. 

The Furnace Has an Oily Smell 

If you own an oil furnace, you could detect this smell if the oil filter becomes clogged. Try replacing it to determine if that resolves the problem. If the smell persists for more than one day after taking care of this step, it could suggest an oil leak. You’ll be better off with help from an HVAC expert to fix this problem. 

The Furnace Smells Like Sewer Odors 

Sewer gas smells quite similar to spoiled eggs, so first rule out the potential for a natural gas leak. If that’s not the source, your home’s sewer lines might have an issue, like a dry trap or sewer leak. Pour water down all your drains, including the basement floor drain, to replenish dried-up sewer traps. If the smell lingers, you should contact a sewer line repair company. 

Contact Winnipeg Supply Service Experts for Furnace Repair 

If you’re still unsure, call an HVAC technician to check and repair your furnace. At Winnipeg Supply Service Experts, we offer comprehensive diagnostic services to pinpoint the problem before repairs begin. Then, we encourage the most viable, cost-effective repairs, along with an up-front estimate for each option. Our ACE-certified technicians can handle just about any heating repair, 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 Winnipeg Supply Service Experts office today. 

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