It can be alarming to notice a burning odor coming from your AC. Your first instinct may be to assume that something has caught fire. However, there’s no need to panic. Oftentimes, a burning smell coming from your AC can be easily resolved by a local HVAC professional.
Below, we’ve listed the most common causes of a burning smell coming from air conditioning units. By learning more about possible triggers for this issue, you can keep your AC unit functioning properly throughout the warm weather months.
Causes of a Burning Smell Coming From You AC
There are multiple potential causes of a burning smell coming from your air conditioning unit. While all may produce a similar odor, it’s helpful to understand the risks of each so that you can preserve the condition of your AC unit.
Your AC Motor is Overheating.
If the motor in your AC unit has worn-out bearings, it will start to overheat. This creates a burning odor. AC motors tend to overheat if:
- A replacement is needed.
- Unit maintenance has been insufficient.
- The motor is the wrong size for the unit.
If you suspect that your AC unit’s motor is overheating, it’s best to seek out professional help from a trusted HVAC team. An expert will be able to tell whether the bearings can simply be lubricated or whether you’ll need to replace the motor altogether. To avoid this issue in the future, make sure that your AC unit is properly and regularly maintained. This will keep the motors’ bearings from wearing out too quickly.
Dust is Burning in Your AC.
If you haven’t had your AC unit running in a significant period of time, dust may have built up inside of it. This typically happens when you don’t use your AC for a few months, such as at the beginning of summer when you start needing air conditioning to keep you cool.
After switching your air conditioning on after months of having it off, the built-up dust will start to burn. This creates a subtle burning smell. If this is the cause of the burning odor coming from your AC, it’s nothing to worry about. Once the dust burns off, the smell will go away. This process usually only takes a few minutes.
If the burning smell lingers for much longer than a few minutes, then your AC is likely to have a different issue.
The Air Filter in the Unit is Clogged.
If the air filter in your A/C unit goes for too long without a replacement, it can get clogged. A clogged filter forces the internal parts, namely the motor and fans, to work harder than usual. This may lead to a burning smell coming from your air conditioner.
When a clogged filter is the cause of the burning smell, you can simply replace it. This should immediately amend the problem. To avoid a clogged filter that causes a burning smell, change your HVAC filters approximately every six months. This time frame can vary depending on the type of filters that your system uses, so ask an HVAC technician for advice if you’re not sure.
Internal Wiring is Burning.
A burning smell that’s similar to rotting eggs or sulfur is a sign of more serious damage to your AC system. Generally, this type of burning smell is an indicator that internal wiring has started to burn.
Your air conditioner’s internal wiring may start to burn if screws become loose or electrical connections deteriorate. Short circuits and breaker defects can also cause this issue.
What To Do When You Smell Burning From Your AC
If you notice a burning smell coming from your AC, turn it off right away. While the issue could be minor, you don’t want to run the risk of damaging internal parts. You can do some investigating on your own to find the problem, such as checking the filter for debris. But, if you’re not sure, don’t hesitate to call a local AC expert. An experienced technician will be able to pinpoint the issue and implement a solution quickly, without the confusion or guesswork of a DIY repair job.