Furnaces can emit a variety of smells as they pump heat through your home. It’s essential to be able to identify when a funky odor may mean the system is leaking gas or breaking down. These are some of the most common residential furnace odors in Allison Park, PA.


If you notice a stale, damp scent when your furnace kicks on, there may be biological growth growing in your ductwork. Excessive moisture often comes from furnace exhaust issues and water leaks. Biological growth could even have started growing on your air conditioner’s coils over the summer.

Rotten Eggs

The smell of rotten eggs or sulfur means natural gas is leaking into your breathing air. Common causes behind gas leaks include compromised heat exchangers and burner issues. Immediately turn off your furnace and main gas supply before calling for heating repairs.

Burning Plastic

If you leave a clogged filter in place for too long, your furnace could start to overheat. This excessive heat can lead to your heat exchanger getting so hot that nearby wires and parts melt.


Kicking on your furnace for the first time after being off for a few months usually creates a mild dusty odor. This occurs as the system burns away accumulated dust. If you continue to notice this smell, your HVAC filters may be clogged and that dust has reached the motor.

Burning Diesel or Oil

An inefficient oil furnace may not burn all of its fuel as it goes through the burner, creating a fog of flammable gas around the system. There could also be an oil or gas leak somewhere.

Carefully monitoring your furnace’s smells can protect your family and comfort. Trust our team at Titan HVAC Inc. to professionally care for all your heating needs in Allison Park, PA.

Image provided by iStock

Pin It on Pinterest

Compliance Settings
Increase Font Size
Simplified Font
Underline Links
Highlight Links