Burning Smell From Air Conditioner (2019)

Do You Have A Burning Smell Coming From Your AC?

If you’re a new homeowner, you probably treat your home like a child. It’s fresh and beautiful, and yet at the same time, it’s stressful and scary because of what could go wrong when you don’t know what to do. If one of those new-to-you issues is a burning smell coming from your AC, then your immediate concern is probably thinking your HVAC system is on fire. Of course, you have to confirm that it isn’t, but the chances are good that it probably isn’t. Still, you don’t want the discomfort of a burning smell throughout your home when you need cold air or heat. So, what does an HVAC system burning smell indicates if it’s not a fire?

The first thing to ask yourself is if you just turned on your heat. If it’s the first time you turned on the heat in a while, but it’s on now because a cold snap rolled through, then you might wind up noticing a burning smell like the heat kicks in.

That’s likely because your heater is just burning off the dust which accumulated during the days, weeks, or months it wasn’t in use. This smell should dissipate in just minutes, or at least soon after that.

However, if your nose catches whiffs of a burning smell while the AC is on and trying to cool your home down, then you need to shut the system down immediately and thoroughly.

If you run your air conditioner while it has something wrong, you’re going to make things much worse. That’s going to mean more money you have to spend on repairs, too. You need to call in an air conditioning repair service or professional to come out and deal with things.

Once your AC is off, there are several reasons why it might have smelled like something was burning.

In the inside unit of your AC, there’s a fan responsible for moving air through your entire home. The motor bearings of that fan can wear out. That would overheat the motor to the point of emanating a burning smell.

The capacitor of the AC is a part that helps that motor run. When a capacitor goes bad, that can also overheat the motor and trigger the burning smell.

Also, a variety of other internal electrical issues inside the AC system can make the motor, or even different parts, to wind up overheating.

Have a trained air conditioner repair technician check the whole circuit inside your AC system to identify the source of any electrical issues present.

6 Reasons for AC Burning Smell Problems And Their Answers:

The following are six possible reasons you are smelling something burning from your AC, plus what you can do to address them:

1) Dust Getting Burned Off:

Problem: If you just turned on your heater, heat pump, or furnace for the first time after a long while, you might notice a burning smell. This is because of months of inactivity, letting the system collect dust. When you first turn it on, the dust is going to burn off. As it does so, it releases a mild burning odor.

Answer: Don’t sweat it. It’s harmless and should go away on its own within moments. It’s the most frequent source of burning odors in an HVAC system, but if it’s still going on 12 or 15 minutes later, then you might have an entirely different issue going on.

2) Clogged Air Filter:

Problem: If you haven’t changed the AC system air filter lately, then it might be clogged. When air filters get clogged down with an excess of debris, it severely restricts airflow. That stains the components, like the fans and motors, throughout the system. This can result in overheating and a burning smell from such components and parts.

Answer: Check the filter for clogging. Replace it with something fresh if need be. It’s a great idea to change air filters monthly.

3) A Broken Capacitor:

Problem: Every HVAC system has its capacitor to power up the motor. When a capacitor fails, the engine might overheat, resulting in that dreaded burning smell. Capacitors can break for many different reasons, whether it’s normal wear and tear, power surges, or overheated circuitry.

Answer: In cases like these, the capacitor is likely to need replacement. Your best bet here is turning the whole system off and let a professional handle it.

4) An Overheating Motor:

Problem: This is a lot like a faulty capacitor, in how a faulty motor might also be the source of a burning smell. In the team, the motor bearings can wear down and create overheating.

Answer: If you’ve never noticed the burning smell before, turn everything off and lubricate your bearings immediately. That should prevent your motor from totally burning out so you can avoid replacing it.

5) An Overheating Belt-Drive Motor:

Problem: Some AC systems have a belt-drive blower instead of a direct-drive blower. These have rubber belts which wear down over time, so you wind up smelling burning rubber.

Answer: These rubber bands have to get replaced sooner or later, so if your burning smell has a rubber tint to it, you’re probably due for a replacement of that particular part.

6) Burning Electrical Components:

Problem: If you smell burning plastic that also has traces of rotten eggs or sulfur, then you might have a hazardous electrical failure somewhere in your system. Your system wiring has plastic components surrounding it, so if that wiring is what’s burning, then the odor is going to be more foul than usual. This happens when you have worn electrical connections, defective breakers, loose screws, or short circuits.

Answer: In cases such as these, turn the system off immediately and entirely. Contact a local HVAC professional or service.