Air Conditioner Smells Like Fish When Turned On: 6 Solutions!

  • If you’ve noticed an unpleasant fish-like smell wafting from your air conditioner when it kicks into gear, you’re not alone. This peculiar fishy smell can be quite the contrast to the crisp, cool air you were expecting. But fear not – there are several potential causes why your AC might be emitting such a fishy smell. In this post, we’ll dive into potential causes that could be causing your air conditioner to smell like fish when in operation and explore some simple solutions you can take to address the issue.

    Whether it’s a dirty filter, microbial growth within the unit, or something else entirely, understanding the potential causes of this fishy aroma is crucial for restoring fresh and clean air circulation in your home. Let’s tackle this stinky situation head-on and get your AC back to emitting pleasant breezes once again.

    Unmasking the Fishy Smell

    An AC can produce different stenches, but the most abhorring of them all is the fish smell. So, I wondered, why does my ac smell like fish, yet I don’t even eat fish at home?

    To my realization, my AC smells like fish because of dirty air filters, burning electrical components, circuit overload, loose electrical wiring, filthy inner components, nearby garbage, or cigarette smoke. 

    So, the issue has nothing to do with having fish around, which is surprising. And when it comes to preventing the fish smell, proper maintenance of the AC and your home and regular inspection of your household electrical components are critical. 

    I’ll walk you through the six issues and their effective fixes. Moreover, we’ll look at a quick guide on eradicating the fish smell from your AC and what causes to check when a car, window, or portable AC starts smelling like fish. 

    Here we go!

    why does my ac smell like fish

    In a hurry? Here’s a quick guide to getting the fish smell out of your air conditioner. 

    Quick Troubleshooting Guide for Fish-Smelling Air Conditioners 

     Likely Cause Recommended Fix 
    1.Burning Electrical Components Call a pro electrician/technician 
    2.Circuit Overload Reduce the circuit overload, and if that doesn’t work, call an electrician
    3.Loose Electrical Wiring Call a pro electrician/technician 
    4.Filthy Inner Components Properly clean the AC’s internal components, especially the evaporators coils, filter, and fishy smell 
    5.Nearby Garbage Get rid of nearby garbage bags and tins 
    6.Cigarette Smoke Discourage indoor smoking and if the smell persists, change /clean the air filter

    Why Does My AC Smell Like Fish?

    Generally, your air conditioner smells like fish due to one of the six reasons below:

    1. Burning Electrical Components 

    Suppose an electrical wire in a switch, light fixture, power outlet, ceiling fan, or appliance is overheating and emitting a fishy smell. The AC will pick up the odor and smell like fish in that case, and that often happens due to a power surge


    Try inspecting the electrical components in the house to see if any are overheating, and then call an electrician. 

    2. Circuit Overload 

    Overheating the circuits is not advisable as it could trigger a fire. Once that’s the case, the circuit burns and produces a fish-like smell that the air conditioner picks up.


    Reduce the number of appliances on a given circuit but if you suspect a fire outbreak or a fishy smell, call a pro electrician. 

    3. Loose Electrical Wiring 

    Due to incorrect installation, the electrical wires in your home could become loose. That includes switches, light sockets, power outlets, junction boxes, and appliances.

    Unfortunately, these loose wires may spark a fire and burn, and the AC will pick a fish odor. 


    Call a professional electrician to check the wiring.

    4. Filthy Inner Components 

    Over time, the air conditioner accumulates dust which cakes up following contact with water to create a damper condition. That’s likely to happen on the evaporator coils and air filter. 

    But the damp conditions may still attract fungi (mold) and bacteria, and such microbes usually have a musty or fish-like smell. So, the air conditioner picks up the smell when running, which is likely to happen when you fail to clean it for so long. 


    Inspect the AC’s internal components, especially the coils, and filter and clean them. Also, check the heat pump and surrounding parts and clean them too. Learn to do this regularly. 

    window air conditioner smells like fish

    5. Nearby Garbage 

    Sometimes the air conditioner picks up the bad fish smell from the nearby garbage. Once it does, it circulates the smell inside the room, and the whole indoor space turns uncomfortable


    Check to see if there are any unemptied garbage bags, garbage cans, or a fishy smell. 

    6. Cigarette Smoke 

    Sometimes nicotine smells like fish when picked up by the air conditioner. So, if someone is smoking in the room, the AC will pick up the smoke odor and make it smell like fish once the air reaches the filter. 


    Change the air filter coils. But first, discourage everyone from smoking within. 

    How Do I Get the Fish Smell Out of My Air Conditioner?

    Now that you know why your air conditioner smells like fish, it’s easy to eliminate the smell. Here are the steps to follow:

    Step 1 – Take Out the Rubbish 

    Look around to see if there’s any rubbish, fishy smell, and clear it. Remove any emptied trash bags and cans. 

    Step 2 – Don’t Smoke Indoors or Near The AC

    Promote a ‘no-smoking indoors’ policy to stop anyone from smoking cigarettes if there are any. And if the smell doesn’t go after that, consider changing the air filter. 

    Step 3 – Clean The Air Conditioner 

    It’s essential to clean the entire air conditioner and not just the air filter. You also have to clean the coils and their internal and external components. Remember, you can clean the filter with a brush and running water. 

    Step 4 – Call A Pro Electrician/AC Technician 

    If you still can’t eliminate the fish smell or suspect an electrical issue, consider calling a certified technician or electrician. Such an expert will help you identify any electrical problems and fix them.

    Window Air Conditioner Smells Like Fish

    Your window air conditioner may smell like fish due to one of these three issues:

    • Electrical issue – Issues like loose or damaged wiring and circuit overload may lead to burning, and the window AC may pick up the burning odor and present a fish smell. 

    • Adjacent garbage – Sometimes, the AC picks up a fish-like smell from the unemptied waste within the compound. So, it’s important not to leave the fishy smell trash lying around for too long.

    • If the air conditioner is too dirty, it may also harbor mold and bacteria, which it may pick up as fish odor. 

    Portable Air Conditioner Smells Like Fish

    Your portable air conditioner is likely to pick up the fish smell under these circumstances:

    • If there is garbage around 

    • If there’s an electrical fault

    • When the AC is too filthy or moldy 

    Clear any nearby garbage and adequately clean the portable air conditioner to eliminate filthiness and fishy smell. Specifically, clean the air filter (or change it) and the evaporator coils. 

    And if you suspect an electrical problem such as a circuit overload or loose or broken wire, call an expert electrician. 

    Car AC Smell Like Rotten Fish 

    Your car AC is most likely smelling like rotten fish because of gas leakage. So, check that; if the gas is not leaking and there is no fishy smell, the issue could be microbial growth within the AC. In that case, look for mold or bacteria growth and clean the unit to eliminate the odor-producing microbes

    portable air conditioner smells like fish

    People Also Ask 

    1. Why Does My New AC Smell Like Fish?

    Your new AC smells like fish because there’s garbage nearby, the unit is mold-contaminated, or someone is smoking in the room. The air conditioner is picking up a fish-like odor in all three cases. But still, the reason could be a burning electrical component or circuit overload. 

    2. Why Does My AC Smell Like a Fish Tank?

    A fish tank-like smell mainly relates to burning plastic parts. So, you have to check the AC to see if some of the plastic parts are overheating, and if they are, call a pro. Don’t forget to check for possible mold contamination, as the AC could be picking the foul odor from the mold

    3. Why Does My Split System Air Con Smell Like Fish?

    Your split system air con might smell like fish because it’s picking up cigarette smoke, foul odor from nearby garbage, or stench from mold growth within the unit. So, check for all these three issues but don’t forget to check the electrical components for possible burning. 

    4. Why Does Foul Smell Come from AC?

    A foul smell comes from the AC because the AC is filthy. The reason could be mold contamination or nearby garbage. But still, the Ac could be picking up cigarette smoke, or an electrical component is overheating and producing the smell. 

    5. Why Does My Car AC Smell Like Rotten Fish?

    Your car AC most likely smells like rotten fish because the gas leaks. It will probably be odor-producing microbes such as fungi or bacteria if it’s not a gas leakage. The latter case mainly relates to poor car AC maintenance. Thus, clean it properly

    6. When I Turn On My Car AC, It Smells Like Rotten Eggs. Why?

    When you turn it on, your car AC smells like rotten eggs because the gas is leaking. If the issue has nothing to do with gas leakage, it’s highly likely due to bacteria or mold growth within the unit. So, check these issues and address them accordingly. 

    7. How Do I Stop My Air Conditioner from Smelling Musty?

    You can stop your air conditioner from smelling musty by cleaning it properly, ensuring you get rid of dust and microbes, especially mold, which are likely to contribute to the musty smell. But again, the mustiness is preventable by properly and regularly cleaning the air filter. 

    8. Is It Normal for Your AC to Smell Weird?

    It’s normal for the AC to smell like dust once you fail to clean it properly. However, it’s normal to smell weird, like fish or rotten eggs. A weird smell usually indicates a problem, such as a filthy unit, burning electrical components, or circuit overload. 

    9. Why Does My Car Smell Weird When I Turn On The AC?

    Your car smells because the gas could be leaking when you turn on the AC. So, check if there is any gas leakage and call a mechanic. If there is none, check for possible mold contamination, as the AC could pick up the mold stench that smells weird. 

    10. Why Does My House Randomly Smell Like Fish?

    Your house randomly smells like fish because your air conditioner picks the fish smell from around. There could be garbage nearby, someone smoking in the house, or a burning electrical component. In addition, the unit could be mold-contaminated, thus fish-smelly. 

    In conclusion, why does my ac smell like fish?

    As shared, your AC smells like fish due to an electrical issue such as burning electrical components, circuit overload, or loose wiring. If that’s not it, it could be that the AC is picking up the odor from nearby garbage, cigarette smoke, or mold contaminants

    Also Read:

    When your air conditioner smells like fish when turned on, it’s crucial to accurately identify the odor. Distinguishing between musty, fishy, or burning smells is essential. Noting the specific location of the odor and paying attention to when it’s most noticeable can provide valuable clues.

    For example, if the smell is strongest when you first turn on the air conditioner after a period of inactivity, this could indicate microbial growth within the system. On the other hand, if you notice a fishy smell coming from the vents regardless of usage time, there may be an issue with stagnant water or organic matter accumulating in the ductwork.

    Electrical Issues as Culprits

    Wiring Problems

    When an air conditioner smells like fish when turned on, it could be a sign of underlying electrical issues. Identifying signs of wiring problems is crucial. Look out for frayed wires, burnt insulation, or unusual sounds coming from the AC unit. These can indicate potential electrical concerns that need immediate attention.

    Faulty wiring in the air conditioner poses serious risks such as electrical fires and system malfunctions. If left unaddressed, these issues can lead to extensive damage to the unit and compromise safety at home. It’s vital to understand that attempting DIY fixes for electrical components in the AC is highly dangerous and should be avoided at all costs.

    Seeking professional assistance for any suspected wiring problems in your air conditioner is imperative. Professional technicians have the expertise to diagnose and resolve wiring issues safely and effectively, ensuring that your AC operates efficiently without posing any hazards.

    Motor Malfunctions

    Unpleasant odors resembling a fishy smell when turning on an air conditioner may also point towards motor malfunctions within the unit. Recognizing indications such as unusual noises during operation or decreased cooling efficiency are key indicators of potential motor issues.

    Motor malfunctions not only result in unpleasant odors but also impact overall performance of the air conditioning system. Ignoring these issues could lead to complete breakdowns or even more severe damage to other essential components of the AC unit over time.

    Exploring potential consequences of ignoring motor malfunctions emphasizes their critical nature; they not only affect indoor comfort but also pose risks to energy efficiency and long-term functionality of the air conditioning system.

    Biological Contaminants

    Mold Growth

    When an air conditioner smells like fish when turned on, it could be due to mold growth in the AC system. Mold thrives in warm and damp environments, making air conditioners a perfect breeding ground. The presence of moisture or organic matter within the unit can promote mold growth. Exposure to mold can lead to various health risks such as respiratory issues, allergies, and even infections.

    If your air conditioner emits a fishy odor, it’s crucial to take preventive measures against mold growth. Regularly cleaning or replacing air filters can help inhibit the accumulation of debris and organic matter that serve as food sources for mold. Ensuring proper ventilation and reducing humidity levels in your home can discourage mold from flourishing within the AC system.

    Another way to prevent mold growth is by scheduling professional maintenance for your air conditioning unit at regular intervals. Professional technicians can inspect and clean the internal components of the system thoroughly, eliminating any conditions conducive to mold development.

    Mildew Presence

    Distinguishing between mold and mildew odors is essential when addressing an unpleasant smell emanating from your AC unit. Unlike musty odors associated with molds, mildew often produces a fishy or dirty sock-like smell when present in air conditioners. This distinct odor is indicative of mildew thriving within the cooling system.

    The specific conditions that promote mildew growth include stagnant water or moisture buildup within the AC unit’s ducts or evaporator coils. Accumulated debris combined with high humidity levels creates an environment ideal for mildew formation.

    To eliminate mildew presence causing fish-like odors in your air conditioner, regular cleaning becomes paramount. Ensuring proper drainage systems are functioning effectively will help prevent water stagnation that contributes to mildew development inside the unit.

    Drain Pan Dilemmas

    Clogs and Overflows

    When your air conditioner smells like fish when turned on, it could be due to clogs and overflows in the drain pan. Signs of clogs and overflows include water pooling around the AC unit, unusual gurgling noises, or a persistent musty smell. These issues contribute to foul odors because stagnant water becomes a breeding ground for mold, mildew, and bacteria. Preventive measures involve regular inspection of the drain line for blockages and scheduling professional maintenance to ensure proper drainage.

    Regular maintenance plays a crucial role in preventing drain pan issues that lead to unpleasant odors from your air conditioner. By upholding air quality standards through regular cleaning and disinfection of the drain pan, you can effectively eliminate foul smells caused by biological contaminants. Maintaining clean filters helps prevent debris from accumulating in the system, reducing the risk of clogs and overflows that result in fish-like odors emanating from your AC unit.

    Air Filter Factors

    Dirty Filters

    When an air conditioner smells like fish when turned on, dirty filters could be the culprit. Neglected filters can lead to foul odors circulating through your home. As dust and debris accumulate, the filter becomes a breeding ground for bacteria and mold, causing unpleasant smells. Recognizing the impact of dirty filters on air quality is crucial for maintaining a fresh-smelling environment.

    Regularly replacing air filters is essential in preventing odor-related issues. Typically, experts recommend changing filters every 90 days or more frequently if you have pets or allergies. By adhering to these replacement intervals, you can ensure that your AC system operates efficiently while also minimizing the risk of unpleasant odors permeating your living space.

    Replacement Schedules

    Establishing a schedule for replacing essential components in your air conditioning system is vital for preventing unwanted smells. Understanding the lifespan of various AC parts allows homeowners to anticipate when replacements are due and avoid potential odor-related problems down the line.

    In addition to regular filter changes, it’s important to consider other components such as evaporator coils and drain pans. These parts can also harbor mold and mildew if not properly maintained, leading to musty or fishy odors when the AC is running. Ensuring timely replacements of these components contributes significantly to maintaining a clean-smelling indoor environment.

    Professional Inspection and Repair

    When to Call Experts

    If your air conditioner smells like fish when turned on, it’s crucial to recognize when DIY solutions may not be enough. Unpleasant odors could indicate mold, mildew, or even a natural gas leak. If you notice persistent fishy smells despite cleaning the filters, it’s time to seek professional assistance.

    Look out for warning signs such as unusual sounds, weak airflow, or inconsistent cooling. These issues might indicate underlying problems that require the expertise of a qualified professional. Promptly seeking expert help can prevent potential health hazards and ensure the efficient operation of your air conditioning system.

    Seeking professional intervention promptly offers several benefits. It ensures thorough inspection and accurate diagnosis of the issue causing the fishy odor in your AC unit. Moreover, it helps in preventing any further damage to the system by addressing underlying problems effectively.

    What to Expect

    When opting for professional odor remediation services for your air conditioner, it’s essential to manage your expectations realistically. A qualified technician will conduct a comprehensive assessment of your AC unit to identify the source of the unpleasant smell accurately.

    The process involved in resolving AC odor issues typically includes deep cleaning of components like evaporator coils and drip pans where mold or mildew may have accumulated. Technicians might need to inspect ductwork for any contaminants causing the foul smell.

    Be prepared for potential costs associated with professional assistance as they can vary based on factors such as the extent of contamination and required repairs. Timeframes for resolving these issues also depend on their complexity but seeking timely professional help is crucial in ensuring a safe and comfortable indoor environment.

    DIY Solutions for Fishy Odors

    When your air conditioner smells like fish when turned on, it’s crucial to explore effective cleaning methods. Start by focusing on the filters, coils, and drip pans. Clean or replace the filters regularly to prevent the accumulation of debris that can lead to odors.

    The evaporator and condenser coils are also susceptible to collecting dirt and grime over time, creating an environment for musty odors to develop. Use a soft brush or vacuum cleaner with a brush attachment to gently clean these components.

    After addressing the internal parts, don’t overlook the drip pan and drain line. Ensure that they are clear of any blockages or standing water which can foster bacterial growth leading to unpleasant smells.

    Implementing safe and efficient cleaning practices is essential in maintaining a fresh-smelling air conditioner. Always turn off the power supply before attempting any cleaning procedures to avoid accidents or damage.

    Long-Term Fixes and Upgrades

    Improved Ventilation

    When an air conditioner smells like fish when turned on, it’s crucial to recognize the role of proper ventilation in preventing unpleasant odors. Improved airflow can significantly enhance air quality by reducing the buildup of musty or fishy smells. By optimizing ventilation within indoor spaces, you can effectively address the issue at its source.

    One way to optimize ventilation is by ensuring that your home has adequate cross-ventilation. This means creating pathways for fresh air to enter and stale air to exit, promoting better circulation throughout your living space. Using exhaust fans in areas prone to moisture accumulation, such as bathrooms and kitchens, can help expel stagnant air and prevent odors from lingering.

    Another strategy is to consider installing a heat recovery ventilator (HRV) or energy recovery ventilator (ERV). These systems exchange stale indoor air with fresh outdoor air while retaining some of the temperature and humidity characteristics of the outgoing air. This not only improves overall indoor air quality but also helps eliminate persistent odors caused by poor ventilation.

    Advanced Filtration Systems

    Exploring options for advanced filtration systems is another effective approach to combatting fishy odors emanating from your air conditioner. Specialized filters designed specifically for odor control can effectively address specific concerns related to musty or fishy smells in indoor environments.

    Investing in activated carbon filters can be particularly beneficial as they are highly effective at trapping and neutralizing a wide range of odorous compounds commonly found indoors. These filters work by adsorbing odor molecules onto their porous surfaces, thereby eliminating unwanted smells from circulating through your home via the HVAC system.

    Furthermore, considering ultraviolet germicidal irradiation (UVGI) technology as part of an advanced filtration system offers additional benefits beyond odor control. UVGI systems use ultraviolet light to destroy airborne bacteria, viruses, mold spores, and other pathogens that may contribute to unpleasant odors while simultaneously improving overall indoor air quality.

    Ensuring a Fresh-Smelling Home

    Routine AC Care

    Consistent care practices are essential. By incorporating routine maintenance into your overall household care habits, you can ensure that your AC operates smoothly and efficiently. Regular inspections and upkeep play a vital role in preventing unpleasant smells when the unit is turned on.

    Prioritizing regular inspections allows you to identify any potential issues with the AC system before they escalate into more significant problems. Cleaning or replacing air filters, checking for mold or mildew growth, and ensuring proper drainage are crucial steps in maintaining a fresh-smelling home environment. By staying proactive with these tasks, you can minimize the chances of encountering foul odors emanating from your air conditioning unit.

    Importance of Air Quality

    Maintaining high air quality standards is paramount for creating a healthy and pleasant home environment. Poor air quality not only affects the comfort of your living space but also has implications for health and well-being. When an AC smells like fish upon activation, it could be an indication of microbial growth within the system or contaminated air circulation.


    You’ve now uncovered the reasons behind that fishy smell coming from your air conditioner. From electrical issues to biological contaminants and drain pan dilemmas, there are various culprits for this unpleasant odor. Remember, a dirty air filter could also be to blame. Whether you opt for a professional inspection or decide to tackle the issue yourself, taking action is crucial to ensure a fresh-smelling home.

    Don’t let that fishy odor linger any longer! Take the necessary steps to address the root cause and enjoy a pleasant, odor-free environment. Your comfort is worth it!

    Frequently Asked Questions

    Why does my air conditioner smell like fish when turned on?

    When your air conditioner emits a fishy odor, it could be due to biological contaminants or mold in the system. These contaminants thrive in damp environments, such as the drain pan and air filter of your AC unit.

    How can I address the fishy smell coming from my air conditioner?

    To tackle the fishy odor, you can start by cleaning or replacing the air filter and inspecting the drain pan for any stagnant water or mold growth. Scheduling a professional inspection to identify and resolve any underlying issues is advisable.

    Can electrical issues cause a fish-like smell in an air conditioner?

    Yes, electrical problems within your AC unit can lead to unusual odors including a fish-like scent. Faulty wiring or components may produce this smell when activated. It’s crucial to have an HVAC technician examine these potential issues promptly.

    Are there DIY solutions for eliminating fishy odors from my air conditioner?

    You can try DIY remedies like cleaning the evaporator coil with a mild detergent solution or using specialized HVAC cleaning products designed to eliminate organic odors. However, if these methods don’t work, consulting with a professional is recommended.

    What long-term fixes and upgrades can prevent my air conditioner from emitting a fishy smell?

    Long-term solutions include regular maintenance such as changing filters and keeping the unit clean to prevent biological contaminants from accumulating. Upgrading to higher-quality filters and installing UV lights within your HVAC system can also help maintain fresh indoor air quality.

Leave a Comment