Why does my AC smell funny?

There’s more than one possible cause for your air conditioner smelling funny the first time you turn it on for the season. Depending on the odor, the problem could be:

  • Mold or mildew in the air conditioner
  • An animal died in or near your HVAC system
  • A gas leak in or near the system
  • An electrical or mechanical break

At Broadley’s, we get a lot of calls around Memorial Day for air conditioning service.

It’s the time of year when people are opening up properties for the summer. A common call is that the AC has a funny smell when they turn it on.

Odds are, no one’s been in a shore house, second home or rental property for a few months. So, if there’s a problem, it’s been left for a while and gotten worse.

Now, some of these smells can indicate a big problem or a safety hazard. But others are caused by something we can clear up pretty quickly.

Either way, it’s a good idea to call us right away if your AC smells bad.

Even if you manage to mask the smell or get rid of it temporarily, you’re not getting to the root of the problem.

We’ll get to the bottom of it quickly, and you can go back to enjoying your summer.

Also, now’s a good time to mention that there’s an easy way to avoid this happening next year: Schedule a tune-up or sign up for our maintenance plan.

We’ll send out a professional to inspect your AC system before you’re ready to turn it on. This way, you head off any problems before they get worse.

And, you’ll be sure your air conditioner is in great shape and running efficiently.

But for now, let’s get to the bottom of what’s happening with your air conditioner.

Dirty Sock Syndrome: When your air conditioner smells musty

We have a name for a stale, musty, and sometimes cheesy smell coming from an air conditioner or other HVAC appliance: Dirty Sock Syndrome.

It’s so named because the smell resembles clothes that have been in a sweaty gym bag for way too long. But, it has nothing to do with sweat or working out.

Instead, the cause is likely mold or mildew.

These contaminants grow in dark, damp areas. If your AC isn’t draining correctly, then it’s creating just the right environment.

When the system dehumidifies the house, the water vapor it captures condenses back to liquid. That’s supposed to drain out of the system.

But, if it doesn’t, it pools somewhere. Depending on where the water collects, you could actually have mold inside the system.

Or, there’s a leak, and the mold is cultivating somewhere else.

Most of the time the mold itself isn’t too much of a problem – especially if we catch it early. Then, it’s easy to clean out.

The bigger problem is that it affects the air quality in your home. People with asthma or other respiratory issues may start having allergy-like symptoms.

A urine or ammonia smell

This is another one where things aren’t always what they seem.

If you smell urine coming from your air conditioner, it’s probably not because someone relieved themselves where they shouldn’t have.

Instead, the problem is probably mold. But, technically, you’re not noticing the fungus itself.

Instead, you’re smelling the mycotoxins, or byproducts, it creates.

These can be more toxic than some strains of mold, so it’s important to have your system checked out immediately.

Sometimes, people also call us saying they smell ammonia rather than urine. Odds are, it’s the same thing.

Rotten eggs

Now, this one’s a little gross. If you turn on the air conditioner and smell rotten eggs, something died somewhere.

It’s common in the winter for animals to find a warm place to stay.

Sometimes, that’s on or near an outdoor AC unit. Or, they’ve managed to get into an air duct somewhere.

Again, it’s often a problem in second homes, shore houses, and rental properties.

We get these kinds of calls a lot in Jersey shore towns like Avalon, Stone Harbor, and Ocean City, NJ.

If no one’s around in the winter to hear a critter scratching around, the problem goes unchecked.

But, once the summer rolls around and something’s decomposing, the smell can travel through your HVAC system.

Usually, the solution here – apart from getting rid of the remains, of course – is to clean out your ductwork. This process gets rid of the smell along with any germs or bacteria.

The cleaning only takes a few hours. You can head out to the beach, and when you come back, the problem will be gone.

Air conditioner smells like skunk or gas

We’ve also had calls where people say they smell a skunk when they turn on the AC. Or, there’s a gas smell coming from the air conditioner.

Usually, a gas leak is to blame rather than a white-striped critter. And, it can be dangerous.

If you smell gas or skunk, open your windows, go outside and give us a call right away.

The culprit here is likely methyl mercaptan. It’s a colorless gas that’s toxic to breathe in and is also flammable.

The thing is, the problem may not be coming from the cooling system itself.

Rather, there could be a leak somewhere else, and the gas is seeping into the system and circulating. That’s why you need a professional to inspect the system as soon as possible.

A burning or gunpowder smell

These aromas usually stem from an electrical problem. A circuit board could be fried, or a motor’s broken, for instance.

It’s likely not creating a health issue. But, you should turn your system off right away. Otherwise, you risk a fire or making the problem worse.

Give us a call, and we’ll be able to trace the problem and let you know if it’s repairable or if you need to consider a replacement.

Call Broadley’s for your air conditioner repair in Marmora, Avalon, Stone Harbor, Ocean City, or Upper Township, NJ. We’ve been servicing the Jersey Shore for more than 70 years and are ready to help you!