7 Tell-Tale Smells That Your HVAC Needs Repair

Keeping your HVAC system up and running is critical if you want to keep your Baton Rouge, LA home at a comfortable temperature. Sometimes your HVAC system will let you know there is something wrong or a breakdown is about to occur by the smells that it emits. If you notice any of the seven smells below coming from your HVAC system, it is important to call your HVAC technician immediately.

Burning Dust

Burning dust is a common smell that can come from your HVAC system, especially if it is the first time that you are starting it up for the year. If you notice the smell of burning dust after starting your system, odds are that it is dust buildup burning off of your heat exchanger and you don’t need to worry. However, if the smell persists after running the system for a while, it could be a signal of other complications that need to be addressed.

Electrical Odors

Electrical odors coming from your HVAC system can occur for a number of reasons. It could be a sign that there is bad wiring somewhere in the system that needs to be addressed by an electrician, or it could be a sign of a more complicated problem such as your motor beginning to burn out. Any electrical smell should be addressed by a professional to prevent your system from breaking down and to reduce your risk of fire.

Rotten Eggs

One of the most nefarious signs that there is a major problem with your system is when you detect the odor of rotten eggs. The gas company puts an additive into your gas so that this smell will be noticeable when there is a leak in your home. If you detect this smell in your home, shut down your system, open up the windows, and go to a safe place outside of the home to call for help.

Oily Smells

Another smell to watch out for from your HVAC system is an oily smell. These smells can have multiple causes, some of which are minor concerns and others which can be a sign of a major problem. No matter the case, these problems should be addressed immediately to prevent further damage. The most common cause of oily smells is an oil leak, which usually requires some tightening of valves. The smell could also mean a clogged burner which can result in a dangerous situation if not fixed.


The smell of acetone, similar to that of strong nail polish remover, can come from your air conditioner, ductless mini-split system, or heat pump when there is a leak in the refrigerant. A refrigerant leak is often accompanied by reduced temperature control and should always be handled by a professional to ensure proper disposal.


In cooler weather you’re not the only one trying to warm up; pests and rodents are also looking to escape the cold. Sometimes these unwanted visitors will end up making their way into your ducts or other parts of your HVAC system trying to seek warmth. Not only can their leavings ruin the quality of air in your home, but if they die in your HVAC system, you can be greeted with the putrid odor of decay coming from your vents. If you smell this, it is best to have your system checked and the pest removed. Your HVAC technician will be able to check the system to make sure they did not cause damage to any of the components.

Chemical Smells

Any type of chemical smell coming from your HVAC system should be investigated. A cracked heat exchanger can emit a smell of formaldehyde and is a serious issue. The heat exchanger is the part of your furnace that will transfer the heat from the combustion chamber. If this part becomes cracked or damaged, it can release dangerous carbon monoxide fumes into the air that can circulate through your HVAC ductwork and out into the air in your home. This can result in a chemical smell throughout your home. If you detect this smell, shut off your system and contact your HVAC technician immediately.

If you notice any of the smells above coming from your HVAC system, don’t let a small problem turn into a large one that can cause damage to your system. Contact One Hour Heating & Air Conditioning® of Baton Rouge at (225) 320-4162 today.