Why Does My Air Conditioner Smell?

Smelly Air Conditioner in O'Fallon, Missouri

If you are dealing with persistent smells in your home, there is a chance that your air conditioner might be the cause. Air conditioners usually help improve your indoor air quality, but if something goes wrong, they might get stinky. It is important to identify the source of a smelly air conditioner, so you can fix the problem right away.

How to Tell If Your Air Conditioner Is Smelling

When you notice a weird smell around your home, the first thing you need to do is pinpoint the source of the smell. It might be tempting to assume that any strange smells are coming from an unemptied garbage can, a clogged drain, or lingering cooking odors. However, an air conditioner is actually one of the most common reasons for a smelly house. If you have cleaned up every source of a weird smell you can think of but are still getting odors, your air conditioner might be the culprit.

To see if the smell is coming from your air conditioner, pay close attention to when you are smelling it. Does it only happen when the air conditioner is on? Do you get a particularly strong whiff of it when you walk past a vent? That might be a sign that your air conditioner is behind the smell. If you think this is happening, take a closer look. Try sniffing right by a vent or opening up your air conditioner to see if the smell is coming from there.

Causes of a Smoky Smelling Air Conditioner

If you are noticing a smoking or burning smell in your air conditioner, it could mean there is something going wrong inside. Air conditioners have a lot of moving parts, and if something is out of alignment, they could grind against each other. Often, this cause of a smelly air conditioner will be accompanied by strange noises or other issues. If you smell something like burning plastic or fire, it could indicate an electrical issue. Short circuits and other electrical issues are very dangerous, so you should turn off your air conditioner immediately if you smell a fire.

Sometimes, a smoky smell just means it is time for a good cleaning. When your unit sits inactive for a while, dust builds up. When the machine clicks on, the power can cause the dust to burn off, resulting in a bad smell. If you or someone else has smoked at your home, the smoky smell might be coming from trapped cigarette odors. Smoke is a particularly strong scent that lingers for weeks. Smoke particles can sit in your filter or on the dust covering your coils. Each time air flows through, it can pick up a few of these particles and cause a noticeable cigarette smoke scent.

Reasons for Musty or Moldy Smells

An unpleasant, musty, mildewy smell is one of the most common types of smells from air conditioning units. This happens because your equipment handles a lot of liquids, and high moisture can cause microbes to grow. When water accumulates in your drain pan or your drip lines, fungus or algae can start to grow. These sorts of organisms have an unpleasant smell that will drift throughout your whole home.

Mold, algae, and mildew can grow on just about every part of your air conditioning system. Some people end up with mildew inside their ducts while others may have stuff growing in their filters. These organisms do more than just stink up the home. They can also cause all sorts of health problems when you inhale them. Your air conditioning can pick up spores and spread them to other spots where whole new infestations can grow. Therefore, it is important to address the problem as soon as possible.

Causes for an Air Conditioner That Smells Like Exhaust

Notice a smell similar to car exhaust coming from your air conditioner? This is not caused by any of the motors in your air conditioner. Air conditioners run from electricity, not internal combustion, so there is no reason for your equipment to smell like exhaust normally. Instead, the smell that you are noticing is most likely from a refrigerant leak. In addition to smelling like exhaust, it may have a chemical or slightly sweet odor.

The refrigerant is a special chemical that helps your air conditioning unit draw heat from the air. It is meant to be closed up inside your coils at all times because it can be very hazardous to your health if released into the air. Smelling refrigerant indicates that you should turn off your air conditioner and open up the windows inside your home. Keep your house ventilated and avoid running the air conditioner until you can talk to a professional.

Reasons for Rotten or Skunky Smells

Some of the most unpleasant types of air conditioner smells are rotten or skunky smells. Unlike mildew or smoke, these scents are impossible to ignore. And unfortunately, if your air conditioner has a gag-worthy smell, the culprit might be something equally gross. These smells often happen because you have a dead animal somewhere in your air conditioning system. Critters like birds, squirrels, frogs, or insects might try to nest somewhere inside your home. If they get trapped and die, your air conditioner can end up circulating the smell throughout your house.

If you have any gas appliances in or near your home, you need to be very cautious about rotten or skunky smells. A sort of unpleasant, rotten egg odor can actually be from gas. It is fairly common for a gas exhaust leak to get sucked into the air conditioner and distributed through the home. This is quite dangerous, so you will need to turn off the air conditioner, turn off your gas supply, and get your utility company to come and check for a leak.

How Can You Fix a Smelly Air Conditioner?

In most cases, a smelly air conditioner can be fixed by removing the source of the smell. This usually just means you need to do a little maintenance and have your air conditioner deep cleaned. Changing filters and cleaning away any mold or other grime can often be enough to help your house start smelling fresh again.

However, sometimes smelly air conditioners happen because your machine is breaking down. There is always a chance that the strange smell could mean leaking refrigerant, broken down belts, or other major problems. Therefore, it is a good idea to get help from a professional. They can take a close look at your unit and see whether or not it is functioning correctly.

If you are dealing with unpleasant air conditioner smells, Hoff Heating & AC is here to help. As O’Fallon’s trusted HVAC service company, we provide prompt and convenient assistance. You can be confident that our technicians can identify the problem and recommend appropriate solutions. Our team is happy to help with a variety of repair, installation, and maintenance tasks for your heating and cooling systems. Call us today to set up an appointment.