Is That Burning Smell From Your Heater Normal?

As the seasons change, our heating and cooling needs change, too. Each fall, as you turn off your air conditioner and turn on your furnace or heater for the first time, you may notice a strange smell coming from your heating vents. Some of these smells are harmless, while others may be dangerous.

Read on to learn about why your heater smells like burning when first turned on, along with some of the most common heater or furnace smells. You’ll also learn what to do depending on the type of smell, including when your heater smells like burning plastic. Read on to get peace of mind if your heater smells like burning.

Common Causes of Burning Smells from Your Heater

If your heater smells like burning, it’s important to be aware of which burning smells are normal and which should elicit concern. Pay close attention to the kind of burning smell you notice to determine whether or not you need to take action or call in help. If your heater smells like burning when first turned on, for example, notice the type of burning smell and, if it seems safe, whether it dissipates over time. Here are some of the possible causes when your heater smells like burning, as well as what you should do in each situation.

Dust Build Up

If your heater smells like burning when first turned on, it’s most likely dust. This is probably the first time your furnace has come on since the previous season, and after months of disuse, dust settles on the heat exchanger, burners, and other heating components. When the burners ignite, the dust burns off, and the odor exits through your air vents. The smell of burning dust is very common when turning on the furnace for the first time in the fall. This smell should dissipate within a few hours at most and is rarely cause for concern. If the odor persists, try changing the air filter. Minimize the reoccurrence of this smell by scheduling an air duct cleaning with a local Aire Serv^® professional before the heating season begins. Performing a pre-season inspection before you turn it on each season can also help.

Clogged Air Filters

If you notice a metallic or burning electrical odor, begin by replacing your unit’s air filter. A clogged air filter restricts airflow and causes your unit to work overtime. If your heat smells like burning and it’s an electrical burning odor, that could also indicate an overheated blower motor in your unit. Under normal operating conditions, the furnace should shut itself off if it begins to overheat. However, if there’s something wrong with this safety feature, your furnace may continue to operate while the motor works overtime, and at that point, the motor becomes dangerously hot. Changing your air filters regularly should help you avoid this issue. However, if the electrical or metallic burning smell persists after replacing your air filter, contact your local Aire Serv.

New Heater Odor

Sometimes, a new unit gives off a smell when you first start using it. If the heat smells like burning, don’t be alarmed quite yet. Dust and particles can accumulate on your unit’s parts, and those will burn off the first time you turn your unit on. Additionally, new parts may have oil, lubricant, or solvent residue on them from manufacturing, which burns off when you first use your unit. Typically, new heater smells will dissipate within the first few hours of use. You can ventilate the area to keep fresh air coming in until the smell is gone. However, if the smell does not go away after a couple of hours, an Aire Serv professional should come and assess your unit to make sure it’s working properly. If your new heater is gas rather than electric, make sure there’s no rotten egg smell, which could indicate a gas leak.

Burning Plastic Smell

If your heater smells like burning plastic, take caution. Units may smell of burnt plastic when their parts are broken or worn out. Parts that may need to be replaced include:

1. The capacitor
2. Plastic-coated wires (that may have caused an electrical fault)
3. The fan belt

These issues should be addressed in a timely manner to prevent further damage to the unit. Your local Aire Serv service professional can help you identify the source of the smell and replace any damaged parts. The smell of burning plastic could also be a sign of an overheated household appliance, a kitchen accident, or a problem with the HVAC system. Go through your home to see if the smell is strongest in one room and, if so, narrow down the source.

Gunpowder Smell

A distinctive gunpowder-like aroma could be the result of a fried circuit board or fan motor. It’s not a good idea to continue running your furnace if it emits this smell. Instead, call a professional to perform an inspection as soon as possible before turning the unit back on.

Smoky or Oily Odor

You are most likely to encounter smoky or oily smells in your home if you heat your house with an oil furnace. You should never be able to smell your oil furnace inside your house. Address the problem first by turning off the unit and changing the oil filter. If the problem persists, turn the unit off and call your local Aire Serv for professional assistance.

Steps to Take If You Smell Burning From Your Heater

If your unit is giving off a burning smell, there are a couple of steps you should take to determine whether or not the smell is something to be concerned about.

1. Turn Off and Check the Heater

As soon as you notice the burning smell, assess whether you think it is a potential concern. If you realize it’s that familiar burning dust smell, you can feel comfortable waiting it out. Otherwise, turn your unit off. Then, check the air filter to see if it is clogged or otherwise shows signs of problems. If the air filter is full, replace it and turn the heater back on. If the smell goes away, you’ve solved the problem!

If not, it’s time to check your vents. Check the outside to look for blockages, and then check to see if anything has fallen into the vents. Small children and pets frequently drop items into vents. If you can see something, feel free to try fishing it out. But if the air filter seems okay and you don’t see anything inside the vents, then leave the heater off. It’s time to bring in the pros.

2. Schedule a Professional Inspection with Aire Serv

If you don’t recognize the smell, or it’s gone on for more than a couple of hours even after changing the air filter, turn the unit off and schedule a professional inspection with Aire Serv. Let us know if this is a problem that needs to be solved right away, and we’ll prioritize your work ASAP. If the smell continues to grow stronger and you cannot identify its source, call your local fire department for assistance. This smell could be indicative of a serious mechanical malfunction or a different electrical problem inside your home.

Are All Furnace Smells Dangerous?

In short, no. Not all furnace smells are dangerous—but they should be investigated. If you smell burning dust that lasts just a few hours and doesn’t return later in the season, there’s unlikely to be anything to worry about. If your heater smells like burning gunpowder, plastic, oil, or rotten eggs, however, that could indicate something serious.

Book Your Appointment with Aire Serv Now!

If you have an unidentified strange smell coming from your heater or furnace or through your vents, call Aire Serv today. Our customer service is available to you 24/7, so you can feel confident that you’ll get a hold of someone right away. Our technicians are here to diagnose and solve all your HVAC issues, including air duct cleaning and maintenance, repair, and replacement for your AC, heater, and furnace. If you need a new unit, our team can help you choose the best heater for you.

You can trust all the services provided by professionals at Aire Serv because our work is backed by the Neighborly Done Right Promise^™. We’ll get the job done right. Call your local Aire Serv location or request an appointment online to get started. If you have unfamiliar or worrisome smells that show up when your heat turns on, we look forward to helping you eliminate them. We’re here for you 365 days a year, 7 days a week. Breathe easier with Aire Serv.

If you can not identify a burning smell in your home, take precautions and call your local fire department for an inspection.