Air Conditioner Smells – Causes And Cures

What is that smell? If you have the air conditioning running and you notice a foul odor, you can be pretty sure that it’s time to have your air conditioner serviced. But before you panic, it might just be something simple and inexpensive that can be easily fixed. Regardless of the problem, to make sure that you and your family are safe & comfortable, don’t wait to call someone. Sometimes those funky smells can be dangerous to everyone in the household.

What’s Causing This Bad A/C Smell?


There are a whole slew of things that could be making your air smell not so wonderful but the most common are:

  • Dirty Evaporator Coils: Over time the evaporator coils in your cooling system collect dirt, dust, and other debris. Regular maintenance can prevent this buildup and nasty smells.
  • Dirty air filters: Air conditioners pull air from your living space into the unit where it is cooled and sent back out. Ingoing air is full of dust and dirt particles which your filter cleans out. If your filter is dirty the air coming out will have all kinds of icky smells.
  • A full drain pan: Moisture from humid air is removed during the air conditioning process and is expelled via a drain or drip pan. If it’s clogged, water will not be able to drain out
  • Faulty or dirty ductwork: Dirt, debris, and other contaminants don’t just accumulate in drains and coils. Your ductwork builds up all kinds of things inside it. If the ductwork is damaged, that increases the odds of foreign substances entering the system. Regular HVAC cleaning and inspections will make sure that your ductwork is clean, undamaged, and free of all that bad stuff.


What Do Different Bad Air Conditioner Smells Mean?


  • Rotten Egg Smell: Natural gas does not have an odor, but energy companies add a chemical that smells like rotten eggs so that it is easily detectable. If you are experiencing this type of smell, DO NOT turn on any lights, electronics, or appliances. Get out of the house immediately and call the gas company.
  • Burning Smell: An air conditioning unit has lots of electrical components and a burning smell can indicate that one of these components IS actually burning. In this instance, turn off the unit at once and call an HVAC expert. It’s never a good idea to try and troubleshoot the problem yourself. Another common reason for the burning smell would be dust burning off after an extended period of inactivity. This would be most common at the beginning of the heating season. If you are unsure we recommend calling an HVAC professional.
  • Dead animal smell: Animals can find their way into just about anything and it is not uncommon for them to enter air ducts where they become trapped and die. The dead animal needs to be removed and the ductwork should be cleaned and sanitized to really get the smell out.
  • Live animal smell: Before they become dead animals, they are using the ductwork as their toilet. The smell of urine or feces will be very noticeable. If you suspect that you have an unwelcome guest, call a pest control expert then call us.
  • Car exhaust or acetone smell: An air conditioner uses fluids that when heated can give of these smells. If this is the odor you are experiencing, chances are you have a leak in your refrigerant line. Not only will you have this unpleasant smell but the leak can cause damage to the unit itself and be hazardous to the environment. While you wait for an HVAC specialist to come check it out, turn the unit off and open some windows to air things out.

Regardless of the smell or what is causing it; if you think something is wrong, it probably is. Texas Ace Heating & Air has the solutions for all these problems and more. Call us at 817-240-6701 or contact us online and we’ll have your home smelling clean and fresh in no time.