The bitter odor of vinegar lingering in the air is immediately off-putting.
When you turn on the air conditioner during a warm summer’s day, it’s never ideal to whiff a strong scent of odor inside the house. This will cause a panic as the scent gets worse with each passing minute.
If you are in this predicament, it’s important to find out what’s going on. There are several reasons for an air conditioner smelling like vinegar.
Air conditioners can start to smell like vinegar when the electric motor is releasing ozone. It’s also common for this sour smell to spread due to the filter malfunctioning, condensate pan getting clogged, mold developing in the ducts, or extra condensation presenting itself on the coils.
This is a dangerous problem to deal with and it should be rectified as soon as possible. If the air conditioner is emitting ozone, this is not a good situation to be in. It will cause harm if left untouched.
This article will look at the main reasons an air conditioner smells like vinegar and what to do about it.
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Reasons Why Your Air Conditioner Smells Like Vinegar
1. Electric Motor Releasing Ozone
When an electric motor has been damaged, it’s common for the ozone smell to increase.
Even a functional electric motor will naturally produce ozone. It will be limited in amount, but you can get a whiff if you get close enough to the motor. Once it is on, it will start to produce this gaseous substance and release it into the air.
However, when the electric motor’s components are malfunctioning, the ozone smell can worsen.
This will make the air conditioning smell like vinegar.
Recommended Solution
The best course of action is to check the wiring near the electric motor. When the wiring splices or breaks, it’s possible for ozone production to increase.
If you fix the wiring, it will ensure the air conditioner works as designed and the smell goes into the background.
2. Extra Condensation On The Coils
When the airflow is impeded due to a dirty filter, the smell of vinegar can spread around the house.
This occurs because the coils get covered with extra condensation.
This is not good for the coils and will cause the AC to lose its efficiency. You will notice sputtering results and it will also start producing ineffective cooling depending on how severe the issue is.
With time, you will have an AC that smells like vinegar and it will be noticeable.
Recommended Solution
To get rid of the extra condensation on the coils, it’s important to clean the coils and change the filter.
This will improve the airflow in the AC and get it back to how it was. Make sure to clean the surrounding elements once you get started. This will act as a preventative solution for potential issues in the future.

3. Mold in the Ductwork
Moisture in the ducts can be a real troublemaker.
You will have serious issues to deal with and this goes beyond the air conditioner. If the AC is smelling of vinegar then it’s best to assess the ductwork in the property.
This might shed light on developing mold inside the ductwork.
It is important to clean the mold and make sure it is removed as soon as possible.
Recommended Solution
Find where excess moisture is developing in the ducts. Assess the mold and make sure to get rid of it right away.
This can be done with the help of a seasoned professional to make sure the mold is removed efficiently. You don’t want mold to be leftover as it will spread again.
4. Condensate Pan Is Clogged
If a window AC smells like vinegar then it’s time to assess the condensate pan.
The condensate pan is right below the water coil in an AC. This pan is solely responsible for collecting any moisture that is dripping from the fixture once it’s on.
Unfortunately, this is a component that can get clogged over time.
Recommended Solution
To resolve this issue, you will want to take a gallon of water and pour it into the overflow pan. This will be located under the air handler.
Continue to assess the pan and see if the water drains into the secondary drain line. If it does, you are good to go and the smell will disappear. If not, continue pouring and watch for the clog to open up.

5. Filter Is Malfunctioning
This is a common reason why an air conditioner is smelling like vinegar.
The sour smell will spread and it is only going to get worse as the filter ages. The more pollutants that accumulate inside the filter, the worse it’s going to get.
Recommended Solution
This is a simple solution.
You will want to change the filter and reconnect it inside the air conditioner. If it is not clicking into place, check where the filter is being held.
You might have to make adjustments to the connection points ensuring the filter is in the right spot throughout the day.
Final Thoughts
These are the reasons your air conditioner smells like vinegar.
An air conditioner can smell like vinegar because the condensate pan is clogged or the electric motor is producing ozone. It is also possible for mold to be in the ductwork, the filter malfunctioning, or there being extra condensation on the coils.
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