Why Does My Furnace Smell Bad? 4 Dangerous Reasons

Woman holding nose because her furnace smells bad

HVAC systems can naturally emit odors that you may or may not notice, but there are some smells that indicate a serious problem that needs immediate attention. There are a few malfunctions that cause specific odors, and ignoring them or thinking you can fix them yourself can put your household in danger.

If you’re asking, “Why does my furnace smell, and what do I do?” here are four distinct odors that are major red flags.

Furnace Smells Like Rotten Eggs

This smell is all too familiar to most people, but if you get a whiff of this in your home, it means there’s a gas leak and it may be coming from your furnace.

If your furnace smells like rotten eggs, get everyone out of the house immediately and call the gas company. Make sure to remain somewhere safe until the leak has been repaired by the proper technicians.

Once the leak has been repaired, bring in a trusted HVAC technician for a maintenance check. Even if your furnace needs additional repairs or even replacement to prevent a potential gas leak in the future, this is not a situation you want to mess around with. Keep your house both comfortable and safe for your family!

Furnace Has an Electrical or “Overheating” Smell

If you notice an overheating smell, this could mean that a motor function or other electrical functions in your furnace are getting too hot. If you smell something similar to hot metal or rubber, it may mean a component of the furnace is actually burning, and there’s a strong possibility for the problem to escalate and cause a fire.

This kind of smell is usually electrically related and can be very dangerous. Turn off your HVAC unit and contact a technician as soon as possible.

Furnace Emits a Burning Smell

Keep in mind that the smell of burning and overheating are not the same. Your furnace may emit a burning smell within the first 24 hours after starting it up for the season due to dust that has built up over the off season.

If the odor lasts longer than 24 hours or if it returns, then it is a dangerous sign. Use the shutoff valve to turn off the furnace, and shut off the gas supply as well. When you call your HVAC repair technician, be sure to tell them the steps you have already taken and where you believe the problem lies.

Furnace Smells Musty

This is a smell you will notice more in your air conditioning unit due to the buildup of moisture that generates within the unit. It can migrate into the air ducts and cause mold, which will result in a musty, mildew-like smell.

When mold develops in your air duct system, your family will inevitably be exposed to breathing it in which can cause serious respiratory problems. However, this is easily fixed with a thorough cleaning of your air duct systems by your repair technician, who can also determine where the excess condensation is coming from and how to remedy it.

If your furnace is emitting a concerning odor, do not hesitate to contact the HVAC repair technicians at Sedgwick Heating! A team of repair technicians is available 24/7 to aid in any emergency heating or cooling situations.