Air Conditioner Smells Bad When Turned On? 7 Astounding Reasons Behind The Stench!

Why air conditioner smells bad when turned on? It might be because of the food you ate earlier that is still going around the room. To get rid of the smell, turn off your AC for a while and open your windows to let fresh air takes place. But there are times that your air conditioner smells for some reason. For example, it might smell due to the following:

  • Decay, rot, and fungus
  • Unclean coils
  • Cigarette smoking
  • Worn-out motor
  • Sewage
  • Dead animals
  • Leaking gas

Remember these causes. It might be that your air conditioner has been smelling like the things mentioned above. You can solve this problem if you first identify the reason why your air conditioner releases a nasty smell when you turn it on. So, keep on reading and learn with us.

air conditioner smells bad when turned on


Reasons Why AC Smells Bad When Turned On

I know you are curious about when an air conditioner smells bad when turned on. There might be a hidden cause for the bad smell. Everyone must know when to check and access their electrical appliances. Air conditioners, in particular, have mechanical parts that can wear out. Seven reasons make your air cooling unit in your home smells bad. Here are they.


Reason #1. Decay, rot, and fungus

Moisture building up in your room is the perfect breeding for mildew and mold. Through your air conditioning unit, it might be that they already established their home there. So, if you smell the air coming from your air conditioner, you can compare that to a horrid stench; mildew and mold are the causes.

In preventing this stench from happening, you need to fix all your water sources, drainages, inspect the air conditioner, and replace its filters. Also, you need to remember that if you have some soil found in the surroundings of your home, like in your basement, you should already cover them.

The best preventive measure for mold and mildew is to have a dehumidifier. This tool will absorb excess humidity and moisture in your room. So, it will be challenging for these molds to grow when the surrounding moisture is low. Lastly, it is better to call a repair service to check and assess what is happening to your air conditioner. Then, the repair service can directly fix it professionally.


Reason #2. Unclean coils

If you smelled the air from your air conditioning unit that is like stinky feet or dirty socks, the reason might be your coils are dirty. Also, it might smell like stagnant water in the air. In fixing this, a professional cleaner will clean the air conditioner, specifically, your evaporator coils, drained condensate lines, and standing water from the back of your cooling unit.

I advise you to ensure that your air conditioner is maintained well every one to two months. The professional cleaning team will pressure clean the parts of your air conditioning unit affected, so do not worry.


Reason #3. Cigarette smoking

When the air smells like someone had taken a cigarette stick, the entire room is affected. Primarily, it can give health risks such as third-hand smoking from the curtains and furniture in your room. In solving this problem, you need to change its air filter. For your convenience, it is best to call a professional cleaner to do it for you.


Reason #4. Worn-out motor

If there is a burning, flaming smell coming from the air in your air conditioner, the enemy might be a worn-out motor. Also, it can be caused by overheating, faulty wiring, or other electrical problem. This problem is severe, so you should be turning off your AC quickly.

It can also be a smell like gun powder coming from the circuit boards and the fan motors of the air conditioner. You should already contact a professional to repair your air conditioner.


Reason #5. Sewage

Sewage smells can go up from faulty pipelines in your home. So, if the odor is coming from your air conditioner, you should assess all the fixtures in your home. Again, call a professional for it to be fixed.


Reason #6. Dead animals

If you smell decaying matter from your AC, there might be a dead animal inside it like rodents. So, quickly turn off your air conditioner and open your windows to recirculate the odor. Then, call your trusted repair service for it to be rehabilitated.


Reason #7. Leaking gas

If you smell rotten eggs, this might be caused by the gas leaked from your AC. Luckily, manufacturers do this for you to detect malfunctions in their system leakage. If you encounter this problem, do not turn on flaming appliances and turn off your AC. Instead, you should call a professional to get rid of the problem. Indeed, many reasons are behind the mysterious stench in your air conditioner. You need to be aware of all of it.



Great! You already know the reasons why the air conditioner smells bad when turned on. It might be caused by fungal infestation, dirty coils, cigarette smoking, worn-out motor, sewage, dead animals, and leaking gas.

So, you should contact your professional repairman to fix the hideous stench coming from your air conditioner. If you want to read more, go here. Thank you very much for reading! See you!

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