If your furnace smells while heating, it’s trying to tell you something’s wrong. We’ve put together a list of the top six furnace smells so you can know what causes them and how to repair 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 occurring when you turn on your furnace for the first time in the fall. Like anything else in your house, 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. Furnace Smells Like Burning Plastic
Cause: Electrical Problem
If your furnace smells like burning plastic or burning rubber, it might have an electrical problem. This smell of burning can be created by melting plastic wire casing, which is a safety hazard. If you’re experiencing a melted plastic smell, turn off your heating system right away and call us at 520-416-5415 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 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 annual furnace maintenance and have working 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 near your furnace, as long as the condensate drain isn’t blocked
- Flu-like symptoms
3. Gas Smell from Furnace
It’s normal for your heating system to let off a little bit of gas when it starts up, 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 daily basis.
Cause: Gas Leak
If your furnace smells like gas continuously, shut it down. If you know where your main gas supply valve is, shut that off too. Then call the gas company and us for assistance.
4. The Furnace Smells Like Sewage
If your furnace sme