Causes of a Burning Smell When Heat Is On

At the beginning of each winter season, temperatures drop, and many homeowners turn on their heating systems for the…
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At the beginning of each winter season, temperatures drop, and many homeowners turn on their heating systems for the first time. More often than not, there will usually be a slightly unpleasant burning-type of smell for the first few minutes that the heat is on. If you find yourself in this situation, it is important not to panic. While some odors could be a sign of potential issues, the smell is usually the result of a benign cause.

If you turn on your furnace or other heating equipment for the first time and there is a quick whiff of a burning smell, it is likely due to excess dust built up in the system. However, if the smell lingers for more than a few minutes, it could be a sign of another issue. Let’s look at some of the causes of a burning smell when heat is on.



A few likely suspects could cause a suspicious odor when you switch on your heating system. When you first turn on your heating unit, a burning smell is most commonly caused by dust buildup on your equipment. If you live in an area that experiences seasonal changes, you will likely not use your heating system all year long. As a result, dust will collect on your unit’s internal parts while it is dormant over the summer.

When you turn your heat on for the first time, you may notice a burning smell for a brief period while the dust burns off. The good news is that dust buildup on your unit isn’t a cause for concern. If this is the reason behind your burning smell, it will go away quickly when the dust burns off. If the smell lasts longer than a few minutes, it could signify another issue.

Dirty Furnace Filters or Air Vents


Heating equipment and furnace maintenance are essential in preventing burning smells and other issues from developing within your system. If your air filters are dirty or the air vents in your system are clogged, you could experience a foul smell when the heat is on. Additionally, poor air filter maintenance could cause mold or mildew to grow in the system or ductwork and create an unpleasant musty and burning smell. It could also create health issues for people with respiratory problems.

If you notice a burning or musty smell that is prolonged when you turn the heat on, you should inspect your air vents and filters. You have several air filters in your home as well as a filter inside of your furnace. You can try replacing all air filters and cleaning your air vents to stop the unpleasant smell. If new air filters and cleaned vents don’t remedy the issue, you should contact an HVAC professional to inspect your heating system and ductwork.

Damaged Electrical Components

While it is less common, a burning smell from your system could result from an electrical issue. In general, the normal operation of your equipment will result in occasional wear and tear. This could lead to damage to electrical wiring or other components. If your wiring is damaged, you might also experience a cracked heat exchanger, overheating blower motor, or other issues. If you suspect that the burning smell coming from your heating system is resulting from an electrical issue, you need to contact an HVAC professional as soon as possible. A qualified technician will locate the source of the smell and address any problems. If left unresolved, you could risk a fire hazard or health problems from exposure to dangerous carbon monoxide.

Many of the issues associated with a burning smell from your heating system have simple solutions. One of the best ways to prevent any problems with your HVAC is to have regular annual maintenance performed by an HVAC specialist. If the burning smell becomes intense or lasts for a prolonged period, you need to contact a professional as soon as possible.