If your furnace smells while heating, it’s attempting 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:

  1. Burning smell from furnace
  2. Furnace smells like burning plastic
  3. Gas smell from furnace
  4. Furnace smells like sewer
  5. Furnace smells musty

1. Your Furnace Smells Like Burning Dust

Cause: Dusty Furnace

If your furnace smells like burning, it’s probably happening when you turn on your furnace for the first time in the fall. Like anything else in your home, your furnace gets dusty over time. This dust burns off when you turn on the heat, resulting in the burning dust smell from your furnace.

2. The Furnace Smells Like Plastic Is Burning

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 caused 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 862-345-6896 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 gets rid of carbon monoxide that’s naturally created during the combustion process.

If it cracks, carbon monoxide can leak into your house. This colorless gas is fatal in heavy concentrations. So, it’s important to have an HVAC professional do annual furnace maintenance and have working carbon monoxide detectors.

Other signs of a cracked heat exchanger include:

  • Soot on or inside the furnace
  • Yellow burner flame, instead of blue
  • Chemical smell from furnace, such as formaldehyde
  • Water near your furnace, as long as the condensate drain isn’t blocked
  • Flu-like symptoms

3. The Furnace Smells Like Gas or Rotten Eggs

It’s normal for your heating system to let off a small amount of gas when it turns on, so you might get a gas smell from your furnace. But it’s not normal to be smelling natural gas or rotten eggs throughout your home on a daily 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 contact the gas company and us for assistance.

4. Furnace Smells Like Sewer

If your furnace smells like sewer, or rotten eggs, you’ll want to ensure you aren’t dealing with a gas leak. If you don’t, the issue 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 solve the issue, you might have a sewer leak, so you’ll want to call a company that handles sewer line repair.

5. The Furnace Has a Musty Smell

If your furnace smells musty, mold and mildew have likely been growing in it for a while.

Cause: Dirty Ductwork

Your furnace uses air ducts to distribute warm air across your house. Mold can grow in the ductwork as time goes on, particularly if you live in a humid climate. You can eliminate the mold by having an HVAC technician do air duct cleaning.

You Can Count on Us for Your Furnace Repair Needs

Troubleshooting your heating and cooling system on your own is hard. Your comfort is our number one goal at Willco Air Conditioning, Refrigeration & Heating Inc., so our pros are here to help you when you need us. When you need furnace repair in Branchville that you can trust, call us at 862-345-6896.