Ottawa’s summer heat is unforgiving, and the last thing you need when you turn on your air conditioner is a blast of something musty or stinky. Bad air conditioner smells are annoying and disruptive—they also mean your AC unit needs serious repairs.
If you’ve turned on your air conditioner and been greeted by a smell that made you turn it right back off, this blog post is for you. Addressing why your air conditioner smells bad and how it’s important for keep a comfortable and healthy home environment during summer months.
In this post, we’ll go over each type of odour, explain what it might mean, and show you how to fix it:
- Moldy Smell
- Dirty Sock Smell
- Burning Smell
- Chemical Smell
- Rotten Egg Smell
- Vinegar Smell
- Exhaust Fumes Smell
- Gunpowder Smell
- Cigarette Smoke Smell
- Steps to Take When You Notice a Bad Smell
- Preventative Maintenance Tips
Common Air Conditioner Smells and Their Causes
1. Moldy Or Musty Smell
A musty or moldy smell usually means that mold or mildew has taken up residence in your AC unit, due to excess moisture accumulating. Mold spores can spread through your home, aggravating allergies and respiratory issues. Not to mention, it’s just plain gross to breathe in moldy air.
Solution
Your first step should be replacing your air conditioner’s air filters, which can trap mold spores. Next, schedule a professional cleaning to eradicate all mold and mildew from the entire system. Don’t run your air conditioning unit until you get this done.
2. Dirty Sock Smell
When your air conditioner starts smelling like a teenager’s gym bag, it’s usually because your evaporator coil is dirty. The evaporator coil can house bacteria and mold which cause that unpleasant odor. This air conditioner smell is not only disturbing but it also means that your air conditioning system isn’t functioning as efficiently as it should.
Solution
Get a professional to clean those coils and freshen up your system. A technician will clean and inspect your evaporator coils to ensure they’re free of grime and bacteria. This will not only get rid of the smell but should also improve how efficiently your system runs and cools your home.
3. Burning Smell
Any burning smell should set off your mental alarm, including one coming from your air conditioning unit. This could be the smell of electrical components overheating or even burning out. It might be due to wires, motors, or other parts getting too hot, which poses a serious fire hazard. Anytime you smell something burning, don’t hesitate.
Solution
Turn off your air conditioning system immediately, then unplug it and turn that room breaker off too. This isn’t a DIY job—burning smells usually mean serious electrical issues. Call a professional technician and have it checked out. Don’t wait: a burning smell could lead to bigger problems or even a fire. Act fast and get a professional to handle it.
4. Chemical Smell
Smell something chemical, like a sweet or chloroform-like odor? That’s a refrigerant leak. Refrigerants like Freon are needed by your air conditioner to cool your home, but they’re toxic if inhaled. A leak both lowers your air conditioning’s cooling ability and is also harmful to your family’s health.
Solutions
First, turn off your air conditioner and stop the coolant leak. Next, don’t try to handle this yourself—refrigerant leaks are dangerous. Call a professional. A trained expert will have the tools and know-how to fix your leak and have your system recharged with the correct amount of refrigerant.
5. Rotten Egg Smell
A rotten egg smell is immediately disturbing, and for good reason. It likely means some small animal (or more than one) crawled its way into your air conditioning unit or ductwork and died in there. In some cases, it could also be bacteria growth in your evaporator coil or ducts. Tough to say which is worse.
Solution
Unless you know what you’re doing, it’s best to let a professional handle your dead animal removal and deep clean to banish that foul odour. They’ll need to safely take apart your unit along with potentially some of your ductwork to first find it and then remove it. Then they’ll clean and sanitize the entire area to get rid of the bad smell and health risks. If it does turn out to be a bacteria problem, you’ll also want them to professionally clean your unit and ducts.
6. Vinegar Smell
A sour, vinegary smell is a big clue that your air conditioner has a blocked condensate drain line. When this line clogs, water sits there getting more and more disgusting and eventually starts producing that vinegar odor. A blocked drain can mean water damage and mold growth if you don’t get it handled.
Solution
Roll up your sleeves and clear and clean that drain line if you’re the handy type. If not, call in a professional to make sure it’s done right. Then make it a habit to have your condensate drain line inspected and emptied regularly.
7. Exhaust Fumes Smell
An exhaust fumes smell is caused by fluid leaks inside the unit, which is a serious issue. When oil or some other fluid touches your motor and burns off, it creates that exhaust odour you’re smelling. Breathing in these fumes isn’t good for anyone.
Solutions
This one is going to require a seasoned professional. Have a technician inspect your air conditioning system, find the leaks and repair them.
8. Gunpowder Smell
Noticing a strange gunpowder smell? This likely means you have a fried circuit board or a fan motor that’s about to give out. Like other electrical issues, this air conditioner smell is no joke and points to a pretty serious problem that could escalate quickly.
Solution
Shut off your air conditioner immediately and call in a professional. Don’t mess around with electrical components. Unless you’re an AC system technician with electrical experience, tackling this on your own isn’t just risky—it’s dangerous. A trained expert can handle the replacement of your unit’s damaged parts and make sure everything is up to safety codes.
9. Cigarette Smoke Smell
An air conditioning unit can sometimes emit a cigarette / tobacco smoke smell. What can happen is the system traps cigarette smoke particles from a previous owner or the surrounding environment. These particles waft into your air filters and ducts, and create a smoke odour that can be baffling if you’re a non-smoker.
Solution
To get rid of the air conditioner smell, you’ll need to change your air filters and clean your ducts. You might be able to do this by watching a Youtube video, but most homeowners have it done professionally. As a side note, regular cleaning and maintenance will stop smoke particles from building up over time and prevent this from happening again.
Steps to Take When You Notice a Bad Smell
So your air conditioner smells bad. Now what?
First step, turn off your smelly air conditioner and stop circulating bad air. If you suspect an electrical issue, it can also be a good idea to unplug it and turn off the electrical breaker in that room.
Next, open up a few windows and let some fresh air in. You don’t want your family breathing in whatever is causing those odours. Get rid of the air conditioner smell and improve indoor air quality with some ventilation.
Third, call in an expert to inspect and fix the issue before it gets worse. Whether it’s mold, a dead critter, or a more serious mechanical issue, professional technicians have the tools and experience to figure out what the problem is and get it fixed.
Don’t wait for the air conditioner smell to go away on its own—it won’t. In fact, it can only get worse, and be a danger to anyone in your home.
Preventative Maintenance Tips
How do you keep these smells from happening in the first place?
Through regular professional AC maintenance and a few easy steps you can do yourself.
Have a professional inspect and tune up your AC unit twice a year. A trained technician will thoroughly service your system, noticing and fixing potential issues before they become major problems. This twice-a-year checkup will also keep your AC unit running more efficiently and cooling your home better and help your AC last a lot longer.
Next, regularly clean your air filter and replace them when needed. Cleaning your air filter will prevent dust, mold, smoke particles and other contaminants from circulating through your home’s air. Check your air filter a few times each summer at minimum and clean them when they need it.
Third, keep the area around your outdoor air conditioner unit free of debris like sticks, leaves, and garbage. Little bits of debris can get inside and block the airflow and cause malfunctions.
Finally, check and clean the condensate drain line periodically. This is a step many homeowners skip. A clogged drain line will sit and grow mold and bacteria.
By sticking to a regular maintenance schedule and these simple DIY preventative measures, you can prevent a lot of the common issues that cause weird and unsafe AC smells.
Get Your AC Repaired With Ottawa Home Services
Don’t let potentially dangerous air conditioner smells ruin your summer vibes. If your air conditioner is smelling up your home’s air, take action now.
Air conditioners can go on the fritz day or night. That’s why Ottawa Home Services provides 24-7 AC repair services anywhere in the Ottawa area, from Kanata to Orléans to Barrhaven.
We fix, service, and maintain all makes and models of central air and ductless air conditioners.
Call us now at 613-604-4777 or request a no-obligation quote. We’re waiting to hear from you!
