Why Does My Furnace Smell Like Rotten Eggs?

16 August 2015
 Categories: , Blog


Furnaces can produce a variety of smells depending on how well they're operating. A rotten egg smell coming from your home's furnace could be indicative of a serious problem and should be addressed immediately. 

Q: Why does my furnace smell like rotten eggs?

A: The rotten egg smell is a natural additive--sulfur--that gas companies mix with gas to alert customers to leaks. The rotten smell indicates that there could be a gas leak coming from your furnace.

Q: What should I do?

A: You should get out of your house, and have your family members evacuate with you. This is especially critical if your furnace is running and the scent seems to be coming from the furnace or the heating ducts. Bring your cell phone so you can call the gas company and furnace repair company once you're safely outside. 

Q: What could cause a gas leak?

A: Gas leaks are often the result of cracks in the furnace's heat exchanger. 

Q: What causes cracks in the heat exchanger?

A: Cracks can happen naturally over a long period of time. Metal contracts and expands when it heats up and cools down. As your furnace ages, this can cause small fissures in the heat exchanger to form. Cracks can also appear prematurely when maintenance on the furnace is deferred or when the furnace is not properly maintained. Failure to change the air filter, for example, can cause the furnace to work much harder than necessary to heat your home, resulting in a variety of problems, including the premature deterioration of the heat exchanger.

Q: Could the smell be coming from something besides the furnace?

A: Sure. The smell of gas is similar to the smell of garbage, skunks and dead animals. If the smell is strong, however, it's better not to take chances--especially if the smell is all over the house and seems to be connected to the operation of the furnace. 

Q: Why are gas leaks dangerous?

A: First of all, gas is combustible. An inconvenient spark in a gas-saturated house could literally cause an explosion. Second, a gas leak would indicate the presence of carbon monoxide, which could asphyxiate you and everyone else inside your house. 

Q: What can I do to avoid this problem in the future?

A: Have a professional furnace repair person service your unit on a yearly basis. He or she can check for cracks, wear and tear and make recommendations for repair. Change your air filter on a regular basis. Also, get a carbon monoxide detector. This won't prevent your furnace from breaking down, but it will give you an early warning when there's a problem. 

For more information or to schedule a furnace repair, contact a furnace repair person like one from Comfort Heating & Air Conditioning, LLC in your area.