African american woman closing nose with fingers, feeling unpleasant scent, suffering from stench, smelly sweaty person bring discomfort, standing over blue background with free space

In general, your furnace should be seen and – other than regular cycling on and off – not heard. And most certainly not smelled! Is your nose getting a whiff of an unusual odor from your furnace? And if so, how can you be sure whether it’s nothing to worry about or requires immediate attention?

Here are four of the most common furnace odors and what you should do about them. Spoiler alert – it’s not always cause for concern.

  1. Musty

When you start up your furnace for the first time during the heating season, you may notice a musty odor. Usually, it means there may be some mold growing in the ductwork or on the air conditioning coil mounted above the furnace. Contact a licensed HVAC technician to conduct a thorough inspection and cleaning. If no mold is found on the coil, it may be time to get your ducts cleaned.

  1. Dusty

On the other hand, if you fire up the furnace at the beginning of the heating season and you smell burning dust, it’s usually nothing to worry about. As your furnace hibernates during the off season, layer upon layer of dust accumulates on the inside. As the components that get hot, the dust burns off and creates that funky smell. The good news is that it usually doesn’t last more than a day or two.

  1. Rotten Egg

If you detect something that resembles the smell of rotten eggs near your gas-fired furnace, shut the furnace off immediately, do not turn any lights or appliances on or off, evacuate your home, and call the gas company’s emergency line from a safe distance. The smell can indicate a gas leak and needs to be taken seriously. It can also be caused by a failed heat exchanger, especially if you have a high-efficiency furnace. This, too, is a serious problem because a bad heat exchanger can pump unsafe levels of dangerous carbon monoxide into your home.

  1. Burning Plastic

If your furnace smells like burning plastic, shut off the furnace and get an HVAC technician out to service it pronto. A burning plastic odor most likely means electrical components and/or wires are getting scorched because of a short or some other malfunction. It could also mean a failing fan motor and that can mean system failure.

You can expect to get 12 to 20 yours out of a modern furnace. However, if you have expensive and more frequent repairs to make toward the end of your furnace’s lifetime, it may be worth retiring old faithful and replacing it with a new, more energy-efficient unit. Keep this rule of thumb in mind when considering repair versus replacement: If the repair costs over 20 percent of the cost of a new unit, you may be better off replacing it rather than trying to repair it. Whether repair, seasonal preventive maintenance, or replacement is in your furnace’s future, contact the home comfort professionals at Anthony’s. We do it all, and to your complete satisfaction.