In most cases, you’ll need professional service to make sure everything’s working properly and you’re not breathing contaminated air. But, knowing what’s happening can help make things go much smoother.
So, in this article, we’ll identify the four most common calls we get and what those smells indicate.
If you notice any of these odors when you begin using your AC in the Fox River Valley this spring, call Compass Heating and Air right away.
There’s a difference between catching the faint whiff of a skunk outside versus the odor seeping in strongly through your vents. If you experience the latter, it’s more likely the sign of a gas link than a small, striped animal.
Whether the leak is connected to your cooling system or close enough to it that your AC is circulating the gas, you need to move fast.
Open all your windows and head outside. Then call your trusted HVAC professionals right away.
You’re most likely smelling methyl mercaptan, a toxic gas that’s also colorless. If it’s seeping out of your AC system, it’s leaking into your house.
Fortunately, its similarity to skunk spray makes it easy to pick up on quickly.
And, of course, if you smell natural gas, follow the same instructions — only, call 911 or ComEd as well. The gas is highly flammable and can cause an explosion.
Next is the smell of rotten eggs coming from your vents. In this case, the cause could be an animal.
Something may have crawled into your ductwork or near your outdoor condenser and passed away. As the body decomposes, the waste and bacteria from it seep into the system.
We see this often in the late spring, as people begin using their air conditioners again. During the winter, and even as the weather gets a little warmer, animals — especially rodents — nest in air ducts or near any equipment that’s warm.
If they pass away there, you’ll notice the signs of it when you begin circulating the air in your home. As it draws from those areas, it will carry the scent, too.
At this point, you’ll need to find and remove the animal. It’s okay if you don’t want to do that yourself.
But, you should absolutely get a professional cleaning at that point. You don’t want any waste or bacteria continuing to seep through the ducts and vents and into your home.
This is especially true in the summer. Once you’re keeping the windows closed all the time, those contaminants have no place to go.
Burning or sulfur, gunpowder smells from your AC indicate something wrong with the system itself. Burning smells are likely caused by an electrical short or a fried circuit somewhere. Sulfur or gunpowder indicated a broken motor or another component.
Unlike the other warning signs here, these won’t affect your health all that much. Sure, it’s unpleasant, but it’s likely to dissipate on its own.
If your system’s still running, however, shut it off quickly. Since this is a sign something’s broken, you don’t want to make the problem worse.
When everything’s shut down, there’s a better chance that we can make some minor repairs. You’ll get your cooling back quickly and it won’t cost you too much.
However, if you continue running it until it stops working, then you’re looking at a much higher bill. It’s likely that the initial break ended up causing more damage because the system was working incorrectly.
Mold and mildew taking root in your air conditioning system can cause a variety of unpleasant smells. The exact causes vary a little, but in general, we’ve heard reports of urine, ammonia, dirty laundry, and cheese.
In fact, the last two have their own name: Dirty Sock Syndrome. It’s the name given to the stale smell that resembles socks that someone left in a gym bag for way too long.
We’ve also noticed people observing it as a cheesy smell, but the cause is the same: mold. Specifically, it’s likely taken hold on the evaporator coil.
Those other smells indicate mold as well — or, more specifically, the byproduct of mold, mycotoxins. These are often more toxic than the mold itself.
In either case, it’s time for a deep cleaning. Either one of these problems will have a negative effect on your indoor air quality.
It’s worth noting, also, that ductless systems can get mold in them as well. It takes root in the air handlers if they’re not properly maintained.
The best way to prevent foul odors and other problems with your AC is through preventative maintenance. You can do some of this yourself by changing the air filters (or cleaning them in the case of ductless systems). And, make sure the area around any outdoor components is clean and clear of debris.
But, an important step every year is getting an air conditioner tune-up. That’s when a service tech cleans the system inside and out. They’ll optimize all the moving parts and replace anything that’s worn down or outright broken.
This inspection should turn up any of the problems we went over in this article. And, it’s much easier to catch them early in the season, before you need the system on all the time.
Plus, you’ll get better comfort from a well-oiled system. It’ll use less energy, too — that means lower electric bills in the summer.