Air conditioning cools the interior of your home in the summer. However, the fresh air in the house can quickly become unbreathable if the appliance emits terrible odors. A stinky air conditioning unit can spoil the interior atmosphere quickly, especially since it is often a rotten egg smell that settles everywhere.

How To Remove Bad Smell From Split AC

What are the causes of bad air conditioning odors? What to do if the air conditioning smells terrible? How to eliminate bad smells? The foul smells from an air conditioner are generally linked to a lack of maintenance and, therefore, hygiene. Here’s a complete guide to getting rid of stink-causing condensation and mold odors.

Why does my split AC smell bad?

If there is a whiff of bad smell in the air from the 2 ton split ac or any capacity, it is clear that there is a problem. Generally, two factors can cause it: the accumulation of dirt in the air conditioner area where the air filters are located or the collection of condensation in the split, which obstructions can cause in the drain.

A lot also depends on the type of smell in the air. They are not all alike. Understanding the kind of smell will help you determine the cause and, consequently, find a quick solution. In case you have any doubts, remember that you can always rely on the knowledge of a specialist technician.

1. Why does my AC smell like sewer?

There are a few reasons why your AC might smell like a sewer. First, there could be a problem with your drainage line. If the drain line is clogged, water can collect in the unit and start to emit an unpleasant odor. Another possibility is that mold or mildew has begun to grow inside the unit. This can happen if the unit isn’t properly cleaned and maintained.

Finally, there could be a leak in the secondary heat exchanger. This part of the AC unit is responsible for exchanging heat between the refrigerant and the air being blown into your home. Freon could be released into the air if there is a leak, causing a distinctive sewage-like smell. If you notice any of these problems, it’s essential to call a professional AC repair technician right away. They will be able to diagnose the problem and make the necessary repairs.

2. Why does my AC smell like mold?

Why does my AC smell like mold

If your AC smells like mold, there’s a good chance mold is present in the unit. Mold is a type of fungi that thrives in warm, damp conditions, making AC units the perfect breeding ground. In addition to causing an unpleasant smell, mold can also cause serious health problems, such as respiratory infections. If you suspect that mold is present in your AC unit, it’s crucial to have the unit inspected by a professional as soon as possible. They will be able to determine the extent of the problem and recommend the best course of action for removing the mold and preventing it from returning.

3. Why does my AC smell of gas?

In most cases, a gas smell coming from the AC unit indicates a problem with the unit’s compressor. The compressor is a vital component of the AC system, and it relies on a small amount of refrigerant to function correctly. If there is a leak in the compressor, the refrigerant can escape and mix with the unit’s lubricating oil. This can cause the lubricant to overheat, causing a burning smell.

In some cases, the gas smell may also come from an issue with the unit’s fan motor. If the motor is not getting enough lubrication, it can overheat and emit a burning smell. If you notice a gas smell coming from your AC unit, it is vital to contact a qualified HVAC technician for service. Trying to repair the best 1 ton split ac in India yourself can be dangerous and may void your warranty.

4. Why does my AC smell like poop?

A common complaint among AC owners is that their unit smells like poop. While this may be off-putting, it is usually not cause for alarm. There are a few simple explanations for why your AC might smell like poop. One possibility is that debris in the unit has begun to decompose. This can happen if the unit has not been cleaned in a while or if an animal has died inside it.

Another explanation is that the coils in the unit are dirty. Dirty coils can cause a musty smell, which some people mistake for the smell of poop. Finally, the smell could be coming from the ductwork. If the ducts are not properly ventilated, they can begin to harbor mold and mildew, which can cause a foul smell.

If you notice that your AC unit smells like poop, the first thing you should do is clean it. This may involve cleaning the coils, the ductwork, or both. If the problem persists, you may need to have a professional inspect and clean the unit.

5. Why does AC smell like rotten eggs?

You’re not alone if you’ve ever noticed a strange, sulfurous smell coming from your AC unit. This unpleasant odor is caused by bacteria buildup in the AC unit’s drainage system. When the AC unit’s evaporator coils become damp, they provide an ideal environment for bacteria to grow. As the bacteria reproduce, they release Sulphur-containing gases, which can waft into your home through the AC vents.

While this smell is undoubtedly unpleasant, it isn’t necessarily harmful. However, the bacterial buildup can eventually lead to clogged drains and water damage if the problem is not addressed. If you notice a foul odor coming from your AC unit, contact a qualified technician to clean the unit and prevent further damage.

6. Why does my AC smell like exhaust?

It’s critical to act quickly if you notice an exhaust-like odor emanating from your air conditioner. This is because the odor source, which is most likely exhaust fumes, is potentially hazardous.

Because air conditioners are powered by electricity rather than fossil fuels, smelling exhaust fumes indicates that fluids inside the motor or other components are leaking. Contacting a specialist for a visual assessment is recommended to figure out what’s causing the issue. It is not advisable to attempt to resolve the problem on your own.

If the scent emanating from your air conditioner is bothering you, don’t hesitate to seek professional assistance.

7. Why does my AC smell like vomit?

There are a few possible reasons for this unpleasant odor. One possibility is that something has died inside the unit. If a small animal has crawled into the unit and died, its carcass can start to emit an unpleasant smell. Another possibility is that mold or mildew has started to grow inside the unit. This can happen if the unit does not get enough airflow or the coils are dirty.

If you notice a musty smell, it’s essential to take action right away to clean the unit and prevent the problem from getting worse. The scent could also be coming from the drain pan in some cases. If the pan is full of water, it can develop a foul odor. Empty the pan and clean it regularly to prevent this problem.

8. Why does my AC smell like a dead animal?

Many homeowners have experienced the unpleasant smell of a dead animal emanating from their air conditioner. While the cause of this problem is often a mystery, there are a few possible explanations. One possibility is that an animal has died inside the AC unit itself. Another possibility is that the smell is coming from the ductwork, which could be harboring a decomposing animal.

It is essential to have the issue diagnosed and resolved by a professional as soon as possible. The smell is incredibly unpleasant, but it could also indicate a severe problem with your AC system. Left unchecked, a dead animal in your AC could lead to mold growth and other issues. Therefore, if you notice a foul odor coming from your AC, don’t hesitate to contact a professional for help.

How to remove bad odor from AC?

To remedy unpleasant odors and restore breathable air in your home, all you have to do is clean your air conditioning. Then, to prevent it from starting again, regular maintenance is expected in the months and years to come. Indeed, air conditioning is a vector of bacteria. Suppose you let the dirt settle, it can cause respiratory or other diseases. It is, therefore, better to clean it regularly to always enjoy healthy air. In the meantime, here’s how to fix a smelly home air conditioner.

1. Cleaning the air conditioning electrostatic filter

Cleaning the air conditioning electrostatic filter

The air is first stirred and then blown inside your house via the wall-mounted indoor unit, also called a split. The air conditioning circuit is equipped with several filters to clean the blown air by filtering dust and other residues.

Your air conditioner has two kinds of filters:

  • The activated carbon filter: filters foul odors.
  • Electrostatic filters: filters out impurities.

It is, therefore, the electrostatic filters, also called mechanical filters, which clog the fastest. These filters must be cleaned twice a month to not let the dust settle and become a veritable nest for microorganisms. To clean your electrostatic filters, soapy water is sufficient. However, if you observe mold or the filter stinks, a disinfectant will be necessary.

To clean each electrostatic filter according to the number of indoor units, the air conditioner must be dismantled according to the manufacturer’s instructions, and the filters removed and cleaned. You can do it yourself because the filters are very easily accessible. In periods of high heat and therefore intensive use, it is recommended to wash them every week.

2. Replace the carbon filter in your air conditioning

The activated carbon filter is responsible for filtering odors. Typically, it is changed once or twice a year depending on the more or less regular use of the air conditioning. However, in case of bad smells, it is to him that you must turn first. Again, the maneuver consists in opening the device to access the filter. Check its condition and change it if necessary. Indeed, the activated carbon filter cannot be cleaned but changed.

To do this, you will do the following:

  1. Remove the air conditioner cover.
  2. Remove the activated carbon filter placed on the front.
  3. Throw the filter in the trash.
  4. Replace the new carbon filter.
  5. Close the hood.

During this operation, you can take the opportunity to clean your mechanical filters and the condensate tray with soapy water and a sponge. If you smell foul odors or notice fungi, conducting a microbiological washing of these elements will be mandatory. This solution effectively removes bacteria, eliminates foul odors, and enjoys purified and healthy air inside your home. Once the assembly is dry, you reassemble everything and close the hood to enjoy the pleasant, odorless air conditioning.

3. Clean clogged condensate line

If the condensate line is clogged or dirty, you can use four methods. Once cleaned, the performance of your best 1.5 ton split ac will no longer be reduced by dirt.

To do this, you will first unplug your air conditioning to work in complete safety. Once this is done, you will remove the condensate pipe, taking care to disconnect it at each end, and you will try one of these four techniques:

  • Pour a glass of bleach down the pipe. The bleach will clean the pipe and dissolve all the impurities. It will be necessary to consider rinsing the conduit before putting it back in place. There are also anti-bacterial treatments specific to air conditioning systems.
  • Stick the tip of a vacuum cleaner against one of the conduit parts. Vacuuming will remove all dust and dirt. It will also allow the cap to be released in the event of an obstruction. Wrap a cloth around the suction nozzle and the duct to prevent any loss of suction and, therefore, power. However, bacteria and mold will not be eliminated with this method.
  • Use a compressed air bomb. Place the tip of the bomb in the outlet of the pipe to bring out all the impurities and the possible plug. However, micro-organisms will always be present inside the ducts.
  • Use a steam cleaner to circulate hot steam inside the air conditioning ducts, which will kill the bacteria and other fungi present in the air conditioning circuit.

In the case of a problem of foul smells with its air conditioning, it is necessary to apply the first method, which will disinfect all the air conditioning air ducts. Dust tends to accumulate in these ducts, causing the appearance of bacteria and fungi. The application of a disinfectant product for air conditioning is the solution to get rid of the causes of these unpleasant odors. You will find air conditioning disinfectants in the form of a spray for easy maintenance.


We hope that this article has helped you to understand how to remove bad smell from split AC. If you have any questions, please feel free to ask us in the comments section below. And remember, if your AC is giving off an unpleasant odor, it’s best to address the issue as soon as possible before it becomes a bigger problem. Thanks for reading.

Frequently Asked Questions (FAQs)

1. How can I make my air conditioner smell better?

First, be sure to regularly clean the filter. A dirty filter can cause the unit to circulate musty air, so it’s important to keep it clean. Second, consider using a fragranced filter. These filters are impregnated with a pleasant scent that will help to freshen the air. Finally, make sure that the area around the unit is free of dust and debris. A build-up of dirt and dust can also lead to musty smells, so it’s important to keep the area clean.

2. Can I put air freshener in AC?

While air fresheners can help to mask unpleasant smells, it is not recommended to put them in AC units. The chemicals in air fresheners can interact with the AC unit’s filters and other components, reducing their efficacy and potentially causing damage. In addition, the fragrance from air fresheners can become trapped in the AC unit, causing it to circulate throughout your home. This can be especially problematic for people who are sensitive to strong smells or who have allergies.

3. Why does my AC smell when I first turn it on?

When you first turn on your air conditioner after a long winter, you may notice that it has an unpleasant smell. This is most likely due to the build-up of dust and debris that has accumulated on the unit over the course of the off-season. In order to remove this build-up and eliminate the bad smell, it is recommended that you clean your AC unit on a yearly basis.

4. Why does my AC smell at night?

When the AC dehumidifies the air, it collects water. An air conditioner that isn’t draining properly can cause mold and mildew to grow, leading to a musty smell coming from the vents. Proper drainage is essential to prevent this problem.

5. What does AC refrigerant smell like?

The air conditioner may emit a sweet, ether-like, or chloroform-like odor from the vents or the unit itself. This is the scent of the refrigerant. Freon is a chlorofluorocarbon (CFC) which helps the air conditioner take heat from the atmosphere to keep you cool, but it can be dangerous to people if not adequately confined. Freon runs through closed copper coils in an air conditioner, but these coils can split and leak AC coolant. The scent of a Freon leak is similar to that of sweet and chloroform. Freon leaks can be dangerous. If you suspect a Freon leak, contact a professional who can diagnose the problem with a Freon leak detector.