ODOR – An unusual smell from the duct-work or registers when the unit is running. There can be multiple sources of unusual odor from an air conditioner. Identifying the type of odor can help identify the source.
Moldy or Musty
It is very common to get a moldy or musty smell when you first start using your air conditioner in the summer months. Condensate produced by the air conditioner mixes with dust that has built-up on the coil and drain pan over the winter and can produce a temporary odor that should go away after using the air conditioner for a couple of days.
Prolonged presence of a moldy or musty smell may indicate a duct-work issue that should be checked by a qualified service technician.
Hot or Burning
A hot or burning smell when the air conditioner is running is generally a sign of a failing blower motor. If you experience this symptom, we recommend that you turn the system “Off” and contact a qualified service technician.
There is actually a condition in air conditioning systems referred to as “Dirty Socks Syndrome”. It is believed to be caused by a microbial growth on the indoor coil that reacts to temperature change and moisture. It is most-often seen in early cooling season (when switching from heat to cool). It produces an odor similar to the smell of sweaty socks. It will typically go away after the air conditioner has been running for a while. There are chemical sprays that can temporarily eliminate the odor.