As the weather turns cold and you swap from cooling to heating your home, you may be worried about strange furnace smells in the air. Learn what the most common furnace smells mean and how concerned you should be about them.
The Furnace Smells Musty
Musty furnace smells generally imply mold growth someplace in the HVAC system. To avoid exposing your family to mold and mildew spores, address this problem as quickly as possible.
A damp air filter can encourage mold, so wiping out the smell could be as easy as replacing the filter. If that doesn’t work, the AC evaporator coil mounted near the furnace may be the root of the problem. This component collects condensation, which can trigger mold growth. You'll want a professional’s help to inspect and clean the evaporator coil. When the problem still won't go away, consider investing in air duct cleaning. This service removes hidden mold, no matter where it’s growing in your air ducts.
The Furnace Smells Like Spoiled Eggs
This is one of the most nerve-wracking furnace smells because it probably indicates a gas leak. The utility company includes a particular substance known as mercaptan to the natural gas supply to make leaks more easily detected.
If you detect a rotten egg smell close to your furnace or originating from your air ducts, shut down the heater right away. If you remember where the main gas supply valve is placed, shut that off as well. Then, get out of the house and call 911, in addition to 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 close to the furnace, this might mean the heat exchanger has cracked. This important component contains combustion fumes, including carbon monoxide, so cracks could pump 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, contact an HVAC professional for an inspection. Consider replacing your furnace if a cracked heat exchanger is the culprit. For your family's safety going forward, make sure you have reliable CO detectors on every floor of your home.
The Furnace Smells Dusty
When you fire up the furnace for the first time after a while, you probably expect a dusty odor to show up for a few minutes. This is the smell of six months’ worth of dust burning away as the furnace wakes up. As long as the smell goes away within 24 hours, 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 clogged, and now fumes are backdrafting into your home. The odor might eventually reach the entire house, risking your family’s health if you let it continue. So shut down the furnace and get in touch with a professional as soon as you can to schedule a repair.
The Furnace Smells Like It's Burning Plastic
Overheating and melting 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 address the problem, an electrical fire could start, or your furnace could experience irreparable damage. Disable the heating system as soon as possible and contact an HVAC technician for help diagnosing and repairing this unusual furnace smell.
The Furnace Has an Oily Smell
If you have an oil furnace, you could notice this stench whenever the oil filter becomes blocked up. Try replacing it to see if that addresses the problem. If the smell lingers for more than 24 hours after taking care of this step, it could imply an oil leak. You should get help from an HVAC specialist to address 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 problem, your home's sewer lines may have an issue, such as a dry trap or sewer leak. Try pouring water down your own drains, including the basement floor drain, to fill dried-up sewer traps. If the smell sticks around, you’ll need to contact a sewer line repair company.
Contact Climate Control Service Experts for Furnace Repair
If you're still unsure, get in touch with an HVAC technician to check and repair your furnace. At Climate Control Service Experts, we deliver comprehensive diagnostic services to determine the problem before we figure out the best solution. Then, we suggest the most viable, cost-effective repairs, alongside an up-front estimate for every option. Our ACE-certified technicians can manage just about any heating problem, 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 Climate Control Service Experts office today.