Why Your Furnace Has a Strange Smell

Turning on your furnace in the winter probably brings some comfort as you enjoy warmer air coursing through your home, but when the air is accompanied by smells you are not keen to, it’s a sign that something deeper may be going on. 

A smelly furnace might not seem like much to worry about, but smells radiating from your vents or the furnace itself nearly always means that it’s time for a furnace inspection by a dependable HVAC service. 

8 Smells to Look For When You Turn on Your Heater this Winter

Funky smells might be nothing to turn your nose to if you’re walking down the street, but when they arise in your home, you should be aware of what they might be pointing to. Here are 8 smells to look out for as you begin to run your heater this winter:

  • Musty 
  • Rotten Egg 
  • Sour
  • Dusty
  • Smoky
  • Plastic Burning
  • Oily
  • Sewage

Musty Furnace Smell

A musty furnace smell pretty much always points to mold growth in your HVAC system. Mold and mildew commonly show up in areas with high amounts of condensation. As you switch your system from running cool air through your house during the summer, to hot air during the winter, you may notice this musty smell. The fix could be as simple as changing out your air filter, but if a new air filter doesn’t take care of the stench, you should consider having an HVAC professional come inspect the unit, rather than submit your family to the effects of breathing in air laden with mold and mildew spores.  

If a fresh air filter doesn’t do the trick, your AC evaporator coil may be at fault. To check on this you need an HVAC pro to inspect the area. If after the inspection and cleaning the coil, the smell still doesn’t subside, it’s time for an air duct cleaning. An air duct cleaning might seem like a big cost upfront, but in terms of keeping you and your family healthy, it is a relatively small price to pay. 

Why Your Furnace Has a Strange Smell

Furnace Smells Like Rotten Eggs

Not only does the rotten egg smell have a terrible stench, it usually always points to a gas leak somewhere in your furnace system. If you are able to turn off the main gas supply valve, do so as soon as possible, as well as turning off your furnace. You should call your gas company right away, and an HVAC company. Take your family and any pets somewhere safe while you wait for an HVAC inspector to arrive. You should not go back into your house until it can be confirmed that there is no sign of a gas leak. 

Furnace Smells Sour

A sour smell radiating from your furnace is most commonly a sign that your furnace’s heat exchanger has cracked. The heat exchanger is an important part of your furnace and it contains carbon monoxide, a combustible fume, that may leak into your home if the exchanger is indeed cracked. 

Carbon monoxide can be deadly, so if you are even the least bit concerned that you or a family member has breathed in the gas, you should call an HVAC professional to test the air around the furnace immediately. If your heat exchanger has cracked you should replace your furnace right away to guarantee the safety of your home. 

Furnace Smells Smoky

A clogged flue is the most likely cause for a smoky furnace smell. Furnaces that run on oil, natural gas, and propane are all dependent on combustion and should vent these fumes out of your house. However, if the flue is clogged, you might be experiencing a smoky smell in your home. 

Furnace Smells Like Burning Plastic

Burned electrical pieces are the most common culprits when your furnace smells like burning plastic. A fan motor that is experiencing issues could also be at fault. Either way, you’ll need an HVAC technician to diagnose the problem correctly. 

Furnace Smells Oily

If your furnace uses oil to run, there’s a good chance you will experience an oily smell coming from your furnace at some point. Replacing the oil filter is the easiest way to determine if the smell is due to a clogged oil filter or if its source is something more serious, such as an oil leak. 

Furnace Smells Like a Sewer

Sewer smell is never a welcome scent in or around the home. If you suspect a sewer smell around your furnace, first make sure it’s not a gas leak, such as carbon monoxide. When you are sure you aren’t in danger of a gas leak, try pouring some warm water into your sewer trap, which can also emit a sewage smell if left dry for too long. 

Call Superior AC & Heat for Furnace Repairs

Turning on your furnace in the winter probably brings some comfort as you enjoy warmer air coursing through your home, but when the air is accompanied by smells you are not keen to, it’s a sign that something deeper may be going on.

A smelly furnace might not seem like much to worry about, but smells radiating from your vents or the furnace itself nearly always means that it’s time for a furnace inspection by a dependable HVAC service.

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When you choose our team to install a new furnace for your home, you can rest assured that the technician sent to assist you is a highly trained expert who will ensure 100% satisfaction. We are always happy to recommend the most affordable and effective solutions for your home or office. Ask us about any of our services today!

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