Heating Odors: Why Does Your Gas Furnace Smell?

Heating appliances can give off various odors during the day or night. Some of the odors are harmless and nothing to worry about, while other odors can be dangerous. If your gas furnace suddenly smells strange, call a heating repair technician fast. Learn more about heating odors and what you should do about them below.

Why Do Furnaces Smell?

It isn't uncommon for a fuel-burning furnace to smell funny when it first comes on. Once the furnace receives enough gas or propane to start up, the fuel system shuts down and the odor disappears. However, fumes or odors that don't go away after the initial start-up can be problematic.

If you detect a rotten egg or sulfur odor around the furnace, shut off the heating system and call your fuel supplier immediately. Also, remove your family and pets from the premises. You could have a major leak in the fuel line. If the odor doesn't smell like rotting eggs or sulfur, call an HVAC technician. Your furnace could need repairs.

What Can a Technician Do About the Odor?

A repair technician will most likely check the fuel lines in your furnace to see if they are clogged with dust or damaged by corrosion. Dust and corrosion can prevent fuel from entering the furnace. After a contractor clears or repairs the fuel lines, the appliance should smell clean again.

If dust and corrosion aren't the causes of the strange odors, an HVAC contractor may check the following parts:

  • burners for old soot and fuel buildup
  • electrical components located deep inside the furnace for damage
  • blower motor for overheating and burnout

If the burners are responsible for the odors, a contractor will either clean the pieces or replace them. If the electrical components are the culprits behind the odors, a contractor will need to replace them completely. The components can melt inside the furnace and permanently damage it. If the blower motor is the reason for the odors, a contractor will clean, oil, dismantle, repair, and replace the part. A heating repair technician may also repair the fan that accompanies the motor. The blower motor fan pushes heated or warmed air through the furnace. If heat backs up in the fan or motor, the furnace will slowly overheat. The entire furnace can fail if this occurs. 

If you're concerned about the odors coming from your furnace, contact a heating repair technician immediately.