Why Is My Aircon Making A Buzzing Noise? (+ How To Fix It)

Air conditioners make a variety of noises while they operate. From whirring, clicking, and humming, these sounds are the by-product of the operating machinery that makes our air cold. However, when your aircon makes a loud buzzing noise during operation, it may be an indication that there is something wrong with your unit.

The buzzing noise that you’re hearing may be coming from loose parts or from small debris lodged in your aircon. It could also be because the wiring has gone bad. Whatever it is, you should take action right away to prevent further damage to your air conditioner.

In this article, we will discuss why your aircon is making a buzzing noise, and what you can do to fix it.

Why your aircon is emitting a buzzing noise

These are the most common causes of the buzzing sound an air conditioner produces. They are arranged based on their level of seriousness, with causes of “least concern” going first (which means you can DIY the fix), and the more serious ones are at the end. The latter causes usually require professional help.

1. Debris inside the unit

Occasionally, small debris can get lodged on the indoor or outdoor part of the aircon. While they are usually benign, they can cause an annoying sound when the air conditioner starts operating.

This usually happens after a storm, which is why you should check your aircon unit after the storm passes. It’s also a good practice to put a cover on the outdoor side of your air conditioner to prevent these small debris from going inside the unit. You can buy one on Lazada for window types and split types (check the sizes before you purchase!)

The fix: open up the aircon and inspect for debris and take them out if there is.

2. Frozen evaporator

The evaporator is the one making the air cold, hence it is usually the coldest part of the aircon. So cold in fact, that it may lead to ice forming on the coils, eventually being spat out of the aircon. The presence of ice on the evaporator can throw the mechanism off balance, and thus make a buzzing sound during operation.

Also, small chunks of melted ice acts as debris that can cause a buzzing noise once your aircon starts operating. (See #1)

Ice on the evaporator is not the problem but a symptom caused by the problem. The real problem is a dirty air filter, or the refrigerant may be leaking.

The fix: First, allow the ice to melt naturally (have some rags ready!). Next, solve this problem at its root by cleaning the air filter.
Also, if you suspect a refrigerant leak, call a technician ASAP!

Warning: Don’t try to scrape off the ice on the evaporator coils – this can lead to long-term damage like Freon leaks when you puncture the coils.

3. Loose parts

The aircon’s numerous moving parts may come loose with age. It may seem like just another annoying problem of least concern, but the parts may come off if action is not taken immediately. Here are the most susceptible parts:

  • Loose screw
  • Condenser fan
  • Blower wheel/fan

Have them fixed immediately to prevent more expensive repairs later on.

The fix: call in a technician to diagnose the problem for you. If the condenser fan or blower wheel is the issue, you may have to have them replaced.

4. Wiring issues

If the buzzing noise sounds “electrical” in nature, it may be because the AC’s wiring is faulty. What you are hearing is electrical arcing, which is when electricity jumps from one point to another. This usually happens due to faulty outlets or loose connections.

Electrical arcing is a dangerous matter, as it produces enough heat to cause electrical fires.

The fix: call in a HVAC technician or an electrician ASAP!

5. Compressor issues

If the weird buzzing noise is coming from the outdoor side of your aircon, then it may be an issue with your compressor.

It may be loose or broken parts within the compressor (serious), lubricant or refrigerant leak (serious), or it may be that the whole compressor has come loose (least concern, but fix immediately). What ever it is, have an HVAC technician diagnose the problem for you.

The fix: Repairing or replacing the compressor of an aircon is a costly affair. Not only does the compressor cost as much half of the price you bought the AC for, the labor cost is also significant owing to the complicated nature of the job. You may be left with no choice but to replace your air conditioner all together.


The buzzing noise coming from your aircon may just be a nuisance at its worst, but it could be an indicator of poor maintenance and faulty parts. Better have it fixed immediately before it complicates in to a bigger problem.


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