There are many possible reasons why your air conditioner smells, from mould and bacteria growth to leaks and odours. Pungent smells can be signs of damage inside or a gas leak. Mould and bacteria can smell badly. And strong smells like those of paint or sour smells can often mean leaks.
There are many possible reasons why your air conditioner, or AC unit, smells. And the type of smell that is coming from your air conditioner can lead to a lot of clues as to the exact cause.
The type of smell being emitted can be caused by something as non-hazardous as cigarette smoke that has gotten caught up in the evaporator coil and filter, or something as potentially dangerous as a gas leak. Depending on the case, you may be able to fix the issue yourself or you’ll have to get in a professional.
Below, we’ll discuss some of the most common smells that AC units emit, the reasons, the precautions to take, and what to do to fix them.
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Why does my air conditioner smell like paint thinner?
Air conditioner units that smell like paint thinner usually leak somewhere. This can be either inside or outside, local to the unit, and seeping inside. Such smells can often mean a toxic or chemical leak, which needs to be taken seriously.
If your air conditioner smells like paint thinner, this is usually a sure sign that there’s a leak somewhere. This can be from a faulty wire or pipe within the air conditioning unit or locally, for example, a crack in the ceiling has let fluids enter the unit. This should be taken seriously, because such a smell can indicate toxic fluids inhabit the unit.
If this is the case, we recommend getting a professional in to have a look at the unit. But, before doing that, you should check your unit. Check the unit for any signs of leaking, such as discolouration around the unit, both front and back, or stains on the carpet below.
Also, check around the walls and ceiling close to your air conditioner for any cracks or openings. If you see such signs, it is likely a leak that’s causing the unpleasant smell.
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Why does my air conditioner smell like vinegar?
If your air conditioner smells like vinegar, it’s probably caused by an accumulation of organic materials or mould. Sometimes, a motor issue can allow bacteria to breed in the filtration system. Sometimes, these can be toxic. The inside will need to be deep cleaned to rid of this smell.
An air conditioner that smells sour, like vinegar, is usually caused by an accumulation of organic materials or mould. It can even be a motor issue in some cases, whereby the smells are caused by ozone chemicals. But, this is less likely the case.
If it is a buildup of mould and other such substances, which is more than likely will be, it’s usually caused by a malfunction in the air filter. This malfunction allows bacteria to breed and multiply. If this is the case, you can replace the filter and clean out the mould.
But, be careful, do not inhale these substances and wash your hands before and after cleaning. Always refer to the user manual before attempting to clean an air conditioner yourself.
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Why does my air conditioner smell like rotten eggs?
Air conditioners that smell like rotten eggs or sulphur is usually a sign that there’s a strong chemical or gas leak. This is not to be taken lightly, because dangerous gases are created to smell this way as a warning sign. You should turn off your gas and evacuate the premises immediately.
If there’s the smell of rotten eggs or sulphur coming from your air conditioner, it almost certainly means there are chemical leaks. This is usually a gas leak, which is getting into your ductwork.
If you smell something akin to rotten eggs, you should leave the air conditioner, turn off the gas at the metre, evacuate the building and call the gas services and emergency services immediately.
Air conditioner smells like cigarette smoke
The odours from tobacco smoke will eventually seep into air conditioners and make them emit the smell. Typically, the odours get stuck in the evaporator coil and filter. The air conditioner will then blow out the odours when they get unstuck. You can get rid of these smells by cleaning your AC.
If your air conditioner smells like cigarette smoke, it almost certainly means either yourself or someone else is smoking in your house and the smells are getting caught in the unit. More specifically, the odours from the tobacco can get caught in the evaporator coil and filter.
Over time, when you power on your air conditioner, these substances get unstuck and get blown out through the vent and into your room or living space. For some people, the smell can be so unpleasant that it can cause headaches. Removing these smells is easy.
To remove these smells and prevent them from becoming a problem, clean your AC unit regularly and change the filter every 30 to 60 days. Better still, smoke outside, and you’ll prevent it from becoming an issue in the first place.
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Air conditioner smells like vomit
If an air conditioner smells like vomit, it’s usually a sign that mould or bacteria is growing somewhere inside. Sometimes, mold or bacteria can be toxic. You can remove the cabin filter and spray disinfectant to get rid of the dangerous spores and unpleasant smells.
An air conditioner that smells like vomit usually has mould or bacteria growing somewhere within. Either way, you don’t want to be inhaling vomit-smelling air, which could prove to be toxic and, in the case of mould, may cause allergic reactions in some people.
Oftentimes, the bacteria or mould is growing on the evaporator fins. You will need to remove the cabin filter and spray disinfectant to get rid of the smell in these cases and to create a healthy ventilation system again.
Air conditioner smells like fish
If your air conditioner smells like fish, it’s probably because plastic components are melting inside. This can often be wires, too. This can be dangerous. We recommend that you should keep the AC off, let it cool down completely, and have it serviced by a professional.
Fishy smells coming from air conditioners are most often caused by the melting of plastic components, which give off this pungent smell. If this smell, especially if accompanied by burning smells, are coming from your AC unit, it is likely a sign that certain components made of plastic inside the unit are burning and melting.
If this is the case, it may not be safe to continue using. You should power off your unit as soon as possible, allow it to completely cool, and have a professional look inside.
Air conditioner smells like urine
Air conditioners that smell like urine most often have a bad mould problem. The types of moulds that give off these smells are often stronger, more dangerous strains, which you should not breathe in. You will need to have the AC unit thoroughly cleaned to rid of these dangerous spores.
Air conditioners that give off the smell of urine usually have a mould problem. This is because moulds give off mycotoxins, or byproducts, which often smell like urine or ammonia. These smells can signal dangerous strains of mould that you certainly don’t want to be breathing in.
If this is the case, be on the safe side and get your AC unit service checked. It may need professional cleaning agents to properly get rid of the byproducts that have built up over time.
