Hansberger Refrigeration Blog: Your AC Repair Resource

Know What to Do About a Burning Smell from Your AC Vent

If you’re expecting only cool comfort this summer but also notice a burning smell from an AC vent, that’s not only an inconvenience — it’s a definite red flag. An air conditioner that is functioning properly should not generate unusual odors — especially those that may indicate that something in the system is overheating.

The best advice is to shut down the AC and get professional service from a qualified HVAC contractor ASAP.  This not only eliminates safety issues, it may prevent more serious, costly damage to critical air-conditioner components. Here are some of the issues that might result in a burning smell from an AC vent.

  • Blower-motor issues. The HVAC’s blower motor, which is installed in the indoor air handler, circulates cooled and heated air throughout the home’s ductwork. Certain conditions may cause this motor to overheat and release a burning smell into the AC airflow. Potential problems causing the motor to overheat include heavy dust accumulation on the motor that is blocking proper ventilation to the unit, as well as wear and tear, such as worn internal motor bearings.
  • Slipping fan belt. A worn blower fan belt may begin to slip on the drive pulley, causing friction and heat that generates a burning smell from an AC vent that resembles rubber burning. In this case, installation of a new fan belt and a pulley-tension adjustment by a qualified HVAC technician is required.
  • Electrical overheating. A central air conditioner includes various electrical components that may release burning smells due to malfunctions. For example, insulation on wiring that is overheating and perhaps melting produces very noticeable odors. Other causes could be short circuits, faulty circuit breakers, or a failing electrical component, such as the large run capacitor that starts the compressor.

Trust your nose. If you notice any burning smell from an AC vent, shut the air conditioner down at the thermostat to prevent a fire hazard. Then, contact the  professionals at Hansberger Refrigeration and Electric Company for quick response and competent service.