Burning smells are among the last odors that you want coming out of your air conditioner. Several factors can play a role in that burning smell, however, and identifying the cause can help you get to the bottom of it. Here’s what you need to know as you seek help from a qualified HVAC professional.
An air conditioner typically has two fans. One fan is located on the indoor part of the unit and the other is in the outdoor portion of your AC unit. Each fan operates with the help of a motor. By design, each motor has bearings that help steer direction and reduce friction during operation. Over time, however, the motor bearings can begin to wear out. When this happens, the friction increases and the motor can begin to overheat, leading to a burning smell. An HVAC professional can perform a maintenance check and lubricate the bearings as needed. If the damage is more extensive, you may need to replace the motor altogether.
Dirty Air Filter
A clogged or dirty air filter can restrict airflow within your AC unit. Restricted airflow forces the blower motor to work longer and harder to push air through the HVAC system. This persistent action causes the motor to overheat, which produces a burning smell. Dirty air filters can have the same effect on heat exchangers. An HVAC professional can change out the filter during a routine maintenance checkup. It is important to address the issue promptly before overheating causes lasting damage to the motor or heat exchangers.
The capacitor is a cylindrical electric component that kick-starts the compressor motor at the start of each cooling cycle. It is located in the outdoor portion of your AC unit. While capacitors are durable, they can also experience damage from overheating, power surges, or gradual deterioration with age. A damaged capacitor can produce a burning plastic smell, and the odor is usually strongest near your outdoor condensing unit. Depending on the extent of damage, you may need a capacitor replacement or a motor replacement. An HVAC technician can diagnose the issue and provide the best course of action for repairs.
Electrical problems can also cause a burning smell. Your air conditioner’s electrical components usually consist of wiring, and these wires have plastic coating or casing. Electrical problems like torn connections, faulty breakers, or short circuits can all cause this plastic coating to melt. This melting plastic creates a strong chemical burning smell. This problem is particularly dangerous because it can result in an electrical fire. If you smell burning plastic from your indoor unit, turn off the unit and contact an HVAC professional for help. Since electrical problems can also smell like burning mixed with ozone or chlorine, you should reach out to a technician if you notice these scents as well.
Torn Fan Belt
Some air conditioner models feature a belt-driven blower fan. The belt is made of rubber and works to spin the fan’s blades. These blades then help distribute air into your home. Over time, however, the belt can become frayed or tear. The worn-out belt can work harder to spin the fan’s blades, resulting in overheating. This overheating causes a burnt rubber smell. If you notice this smell, turn off the unit and contact an HVAC services company. A technician can replace the fan belt for you.
Singed or Scorched Dust
This is usually the most benign reason for a burnt AC smell. Many homeowners report a mild burning smell when they turn on their units for the first time of the season or after several months of disuse. When an HVAC unit sits dormant for a period, dust can settle in the ducts or other components. But when the system kicks back into gear, the internal components start to heat up and burn off the dust. This results in a slightly singed or burned smell. The good news is that this smell should dissipate quickly. If the smell persists for hours or even days, you will need to contact an HVAC professional to troubleshoot or diagnose the issue.
Get Help Today
No one wants to inhale burning smells from an air conditioner. Fortunately, a reputable HVAC services company can help. Element Air LLC provides air conditioner inspections for homes in Louisville, KY and surrounding areas. We offer AC installation, troubleshooting, maintenance, and repairs. We also offer furnace installation for the winter and a maintenance membership program to keep your HVAC system healthy all year long. Contact Element Air LLC to tackle all your HVAC needs.