If your furnace smells while heating, it’s trying to tell you something’s wrong. We’ve compiled a list of the top six furnace smells so you can know what causes them and how to fix them. These include:
- Burning smell from furnace
- Furnace smells like burning plastic
- Gas smell from furnace
- Furnace smells like sewer
- Furnace smells musty
1. Your Furnace Smells Like Burning Dust
Cause: Dusty Furnace
If your furnace smells like burning, it’s likely happening when you turn on your furnace for the first time in the fall. Like anything else in your home, your furnace accumulates dust over time. This dust burns up when you turn on the heat, resulting in the burning dust smell from your furnace.
2. Furnace Smells Like Burning Plastic
Cause: Electrical Problem
If your furnace smells like burning plastic or burning rubber, it might have an electrical issue. This smell of burning can be created by melting plastic wire casing, which is a safety issue. If you’re noticing a melted plastic smell, turn off your heating system right away and call us at 507-387-6596 for furnace repair.
Cause: Overheated Motor or Cracked Furnace Exchanger
An electrical burning smell could also mean your furnace motor is overheated or the heat exchanger is cracked. The heat exchanger safely exhausts carbon monoxide that’s naturally produced during the combustion process.
If it cracks, carbon monoxide can leak into your home. This invisible gas is fatal in large doses. So, it’s important to have an HVAC professional do routine furnace maintenance and have functional carbon monoxide detectors.
Other symptoms of a cracked heat exchanger include:
- Soot on or inside the furnace
- Yellow burner flame, instead of blue
- Chemical smell from furnace, like formaldehyde
- Water around your furnace, as long as the condensate drain isn’t blocked
- Flu-like symptoms
3. A Gas Smell Is Coming From the Furnace
It’s normal for your heating system to give off a little bit of gas when it turns on, so you might get a gas smell from your furnace. But it’s not typical to be smelling natural gas or rotten eggs throughout your home on a regular basis.
Cause: Gas Leak
If your furnace smells like gas frequently, turn it off. If you know where your main gas supply valve is, shut that off too. Then call the gas company and us for help.
4. The Furnace Smells Like Sewage
If your furnace smells like sewer, or rotten eggs, you’ll want to ensure you don’t have a gas leak. If you don’t, the problem could be with your sewer lines and not your furnace. This is especially true if it’s been very dry lately.
Cause: Dry Sewer Trap or Sewer Leak
If you suspect your sewer trap is dry, you can try putting some water down the floor drain in your basement. If that doesn’t fix the issue, you might have a sewer leak, so you’ll want to call a company that does sewer line repair.
5. The Furnace Has a Musty Smell
If your furnace smells musty, mold and mildew have probably been growing in it for some time.
Cause: Dirty Ductwork
Your furnace uses air ducts to send warm air across your house. Mold can grow in the ductwork over time, particularly if you live in a humid climate. You can get rid of the mold by having an HVAC technician do air duct cleaning.
Depend on Us for Your Furnace Repair Needs
Troubleshooting your heating and cooling system by yourself is hard. Your comfort is our number one priority at Northern Comfort Inc, so our pros are here to help you when you need us. When you need furnace repair in Mankato area that you can trust, contact us at 507-387-6596.
