Why Does My Air Conditioner Smell? Common Causes and How to Fix It

Trane air conditioner unit with a musty smell; common causes and fixes.
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Keeping your air conditioning system up and running is critical if you want to keep your Conejo Valley home cool and comfortable. Sometimes your AC will tell you something is wrong by the smells it emits. But what can cause these exhaust fumes or egg-like, musty, burning scents? And better yet, how can you eliminate these unpleasant odors?

After all, you installed your air conditioner to cool down your home, not stink it up with unpleasant AC smells, some of which might even be potentially dangerous. Here’s what you need to know about the seven common causes of the odor coming from your air conditioner and tips on eliminating them.

Air Conditioner Smells Like a Car’s Exhaust

Does the smell coming from your AC remind you of a car’s exhaust fumes? Your AC unit likely has a refrigerant line leak. If you’ve also noticed that your AC unit isn’t performing as efficiently, you’re definitely dealing with an AC refrigerant leak. Your refrigerant line may leak hazardous chemicals that are bad for the human body and the environment.

To prevent damage, quit searching “How to remove bad smell from split AC?” and call an expert immediately to investigate the issue. You can ventilate your home to eliminate the smell while waiting for HVAC repairs.

AC Smells Like Something Is on Fire

A faint whiff of burning that occurs when you first turn on your HVAC system is usually nothing serious. If it doesn’t dissipate by itself, and your AC smells like a more pungent burnt or gunpowder odor, you might be dealing with a short circuit, overheating motor, or loose sparking wiring.

If you’ve just turned on your AC and it’s emitting a faint burning smell, wait several minutes to see whether it dies down. For more pungent burning smells, shut off your AC immediately and contact an HVAC company for air conditioning repairs.

AC Smells biological growthy or Musty

If your home’s air conditioner smells musty or biological growthy, you’re possibly dealing with frozen evaporator coils or a clogged drain line. While frozen evaporator coils and clogged drain lines are usually the culprits, your AC might smell musty because of the following:

  • biological growth or mildew in your air ducts and vents
  • Clogged filters
  • Leaking air ducts
  • Dirty evaporator coils

If your AC’s smell reminds you of a musty, biological growthy basement, it’s time to schedule AC cleaning services. Don’t let musty AC smells prevent you from having a cool and comfortable home. Contact Conejo Valley Home Services for AC service in the Conejo Valley.

AC Smells Like Rotten Eggs or Gas

The dreaded rotten egg smell is the most worrying odor that your HVAC system can emit. An AC that smells like rotten eggs or sulfur almost always signals a natural gas leak in your house. Natural gas is a hazardous substance that can lead to fire or reduce oxygen levels in the bloodstream with severe, often fatal, consequences.

If you smell gas, switch off your gas supply immediately and call your gas company to report the leak and schedule an inspection.

AC Smells Like a Decaying Animal

What about an AC smell that’s not quite rotten eggs, but it’s something rotten? You could be dealing with a dead pest if you notice a putrid smell from your AC. Creatures such as birds, mice, and rats can crawl into your air ducts and die there, emitting a foul odor when they rot.

Start by calling pest control to remove dead animals, then contact your HVAC company to clean the ducts afterward to eliminate the smell permanently.

Air Conditioner Smells Like Chemicals

Your air conditioner should not smell like chemicals. It uses several fluids, but none of them should cause a noticeable odor. If your AC smells like sweet chemicals, you’re most likely dealing with a refrigerant leak. If it smells like formaldehyde, you probably have a cracked heat exchanger in your furnace and need to get it checked immediately. It’s best to contact an AC specialist to diagnose the source of the chemical smell. In the meantime, ventilate your home for your family’s safety.

AC Smells Like Gunpowder

Smelling gunpowder in your air conditioner? You’re likely dealing with a fried circuit board, power cord, fan, or compressor. The gunpowder AC smell is often caused by burning one of these components, so you should quickly turn off your air conditioner and contact your HVAC technician immediately.

If your AC smells musty after winter, the burning smell could be from the dust buildup burning off of your heat exchanger. You don’t need to worry if the smell disappears after a few minutes. However, if the smell persists after running the system for a while, consult a professional if you are unsure.

Air Conditioner Smells Like Cigarette Smoke

If you just bought your Conejo Valley home and are using the HVAC system for the first time, tobacco residue in the ducts and vents could create an odor of cigarette smoke in your home.

If you smell stale cigarette smoke when you turn on your air conditioner, start by changing the air filter, and if it doesn’t work, you need to schedule a professional cleaning and tune-up. Don’t let a minor problem turn into a large one that can cause damage to your HVAC system. With some HVAC maintenance, you can prevent the above smelly air conditioner issues.

Keep Your AC Clean and Safe

If you are experiencing an unusual smell when you turn on your AC system, don’t hesitate to call the experts at Conejo Valley Home Services to diagnose and fix the problem. We have been a locally owned and operated business since 1979, specializing in air conditioning, replacement, and fast AC repairs.

If you need fast and reliable air conditioning service, Conejo Valley Home Services can be at your side that same day. Contact us online or call (805) 499-0448 today!

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Sherrielyn Andersen profile picture
Sherrielyn Andersen
0 days ago
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EOMASK838e20a047d016XThere are 2 HVAC units at my home. The upstairs unit stopped working during the hottest days in SoCal so I called Conejo Service and received a next day appointment. The person who answered the phone was very professional and helpful. I was given a 2 hour window for the service and told the technician would send a text 15 minutes prior to arrival. I cannot tell you how many times I've heard this, only to be disappointed when no notice was sent by a technician. Juan sent a text, as promised, And arrived within the 2 hour window. Luckily for me, he arrived on the front end of the window vs the tail end. Prior to entering my home Juan donned shoe covering so as to not track dirt into my home. I joked about how many times he must do that a day bc he took the covers on and off every time he went in or out. He diagnosed the issue with the unit. He explained and showed me exactly what he discovered and discussed the options for repair. I mentioned that I was having an issue with the second unit as well. He went through the same process as he had done with the first unit. I elected to have him service the second unit as well. Both units are old and will need replacement, but I can wait in a cool house now while I budget that expenditure. I will absolutely use this family owned business again in the future.EOMASK838e20a047d017X
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Mia Charlie profile picture
Mia Charlie
1 days ago
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EOMASK838e20a047d018XWe were very pleased with the electrical service received from Ron and Jorge. They did an awesome job adding electricity to 2 bidets. With one of them, the electricity had to be pulled from the garage into the bathroom. It was done seamlessly. Everything was cleaned up and straightened out when they were finished. The plumbers Miguel and Otto also came to fix a leaking toilet. Once again, they were fast and efficient. They answered several other plumbing questions I had after they finished the job. Great job by all!EOMASK838e20a047d019X
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Ravi Narla
1 days ago
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EOMASK838e20a047d020XJuan diagnosed the unit, performed the repair and got the air conditioners to work.EOMASK838e20a047d021X
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Philip Stafford
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EOMASK838e20a047d022XI had a schedule maintenance. I met technician David that came to my home he looked over the entire HVAC system and cleaned my HEPA filter. Im very pleased with him overall. I recommend Conejo Valley services and specially recommend David Gonzalez service technician.EOMASK838e20a047d023X
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Terry Hoffman
1 days ago
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EOMASK838e20a047d024XJorge Garcia was terrific. Professional and Polite. He is meticulous , even with a complicated Electrical system.EOMASK838e20a047d025X
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Kathy Hollis
1 days ago
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EOMASK838e20a047d026XBrandon with electrical install was fantastic! Excellent job of installation and extremely professional & nice. Very kind to colleagues. A+EOMASK838e20a047d027X
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Teeba Bloomer
1 days ago
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EOMASK838e20a047d028XWe had a really great crew who was very professional and communicated often. Even letting me know when things might be loud so I could choose to step outside. Alfredo was especially kind and really took the time to teach me ways to turn my vents in order to make the most of the airflow.EOMASK838e20a047d029X
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Scott
1 days ago
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EOMASK838e20a047d030XConejo Valley Plumbing came through for us in a pinch. We needed a plumber ASAP because our water to the house needed to be shut off due to a broken valve in our garage. Plumber Ronnie Stoner responded and promptly made the repair. Really appreciate the excellent service Conejo Valley Plumbing and all of its services have provided for us over the past 11 years (also replaced our roof and HVAC system). The company consistently provides peace of mind with its services. Thank you!EOMASK838e20a047d031X
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Mia Charlie
2 days ago
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EOMASK838e20a047d032XElijah Ritz and Vartan Demirjian along with 2 other workers provided outstanding plumbing services at my house today. They made me feel very comfortable by ensuring me they wouldn’t leave unless I was totally satisfied. They installed 3 difficult faucets and 2 toilets with bidets. The toilets/bidets are amazing…if you can call a toilet amazing. Elijah and Vartan were totally professional and knowledgeable. Elijah oversaw and checked-up on work throughout the project. He was great. Two thumbs and 5 stars!!EOMASK838e20a047d033X
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Amanda Sifuentes
2 days ago
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EOMASK838e20a047d034XEric was great. Professional and kind. He was done quickly and went above and beyondEOMASK838e20a047d035X
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Stuart Watt
3 days ago
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EOMASK838e20a047d036XThank you Matthew! Shout out to Matthew, a plumber at Conejo Services! Matthew resolved several sticky and unique plumbing issues. He showed creativity, commitment and determination to get the issues fully resolved. Thank you!!EOMASK838e20a047d037X
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Lynne Smith
5 days ago
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EOMASK838e20a047d038XCorey just left our house and he did a great job with our sink drain and new AC condensation line draining into the sink. Thanks Corey and Conejo Services!EOMASK838e20a047d039X
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Nancy Scanlon
5 days ago
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EOMASK838e20a047d040XVery professional! Quick service very nice and thank you for my plants Cole.EOMASK838e20a047d041X
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Estefany Sampablo
6 days ago
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EOMASK838e20a047d042XElijah Ritz is very professional, and explained everything clearly before starting the repairs needed. The repair was quick and executed perfectly. I’m very happy with his work and highly recommend him to anyone in need of reliable plumbing services.”EOMASK838e20a047d043X
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Mary Arnold
6 days ago
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EOMASK838e20a047d044XReplaced angle stops and expansion tanksEOMASK838e20a047d045X
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Sholah Yi
6 days ago
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EOMASK838e20a047d046XRonnie came out to do an annual 65 point inspection. He did a good job of finding areas of my house that needed plumbing repairs. Also provided me with estimates on replacing a water heater.EOMASK838e20a047d047X
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M Lee Bello
6 days ago
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EOMASK838e20a047d048XMiguel & James were terrific plumbers. Proxy, arrived early, polite, smart and friendly. Would hire them againEOMASK838e20a047d049X
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Drew Newman profile picture
Drew Newman
7 days ago
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EOMASK838e20a047d050XConejo is the BEST!!! Ronnie fixed everything. Professional, kind and funny. Definitely choosing Conejo for all my plumbing needs.EOMASK838e20a047d051X
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Kyle Shaw profile picture
Kyle Shaw
7 days ago
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EOMASK838e20a047d052XPlumbing maintenance was a breeze. Ronnie was prompt and on time and had great service.EOMASK838e20a047d053X
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Lauren Anderson
8 days ago
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EOMASK838e20a047d054XI’m really glad I happened to find Conejo Services. It’s been one of those crazy months where EVERYTHING keeps breaking or falling apart. We’ve had multiple plumbing issues in the past two weeks; and both times Conejo sent James as our plumber. James is honest, kind, thorough, and goes above and beyond to take good care of homeowners. Beyond James’s professionalism, Conejo has impressed us with their communication style. They text confirmations promptly and also send a photo of the service technician will be, so you are 💯 confident who is knocking on your door is who they say they are. Seriously relieved to find such a trustworthy company—which is rare these days.EOMASK838e20a047d055X
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