Air Conditioner Makes Loud Noise When Starting: 6 Alarming Sounds!

Does the noise from your AC bothering you, and you are curious why your air conditioner makes loud noise when starting? There are about six various sounds and explanations waiting for you below to satisfy your curiosity.

What do you think those sounds mean? You will eventually find it annoying to hear various sounds coming from your air conditioner.

air conditioner makes loud noise when starting

Note that these sounds are your unit’s way of telling that there’s something wrong. But fear not, since this article will assist you. So, don’t get off track!


Different Sounds Your Air Conditioner Makes When Starting

Once you notice the slightest changes in your unit, you should take immediate action because it could be severe damage and lead to more hazardous problems. Your AC has the responsibility to cool your room and improve air quality.

But you’re responsible for making the best out of your purchase. Different sounds have various causes. And by knowing the reason, you’ll learn how to fix it. So, we present to you various sounds produced by your unit and their possible causes.


Sound #1. Banging

You could associate the sound with many components of your AC. It ranges from soft banging sounds to severe and most disturbing. Here are the possible causes behind the sound:


Cause #1. Stuck debris

If you own a window air conditioner and the exterior side is exposed to bushes and shrubs, there’s a high chance that there will be sticks and leaves inside your unit.

Small stones and hard materials can swing back and forth your AC components, and they would produce a banging sound. However, this situation has a high rate of urgency, and you should take immediate action.


Cause #2. Loose fan

There are times when AC blowers or fans get loose, and they would make contact with their surfaces, such as the materials that cage them. We should fix this situation as soon as possible.

You can observe this by hearing a loud and constant banging sound of metals. So, when you try to check it, turn off your unit. Because if you failed to do this, it might cause severe damage to you and your surroundings.


Sound #2. Screeching

Oh, most of us do hate this sound—the sound of screeching metals. When it’s coming out of your AC, it’s most likely to be caused by your fan’s metal blades or its motor bearing. Also, the fan might be in an improper angle position.

So, it would result in the blades being in contact with its cage, and it will produce a screeching sound while rotating. Meanwhile, this sound can also result from faulty metal bearings or high pressure in your AC compressor. And you should have these problems fixed.


Sound #3. Clicking

We always hear a clicking sound from our AC. But if it gets faster and does not stop, it could be a dangerous problem. So, only use it once you’ve figured out what’s going on. There are two possible explanations for this sound that could be interrelated.

The first one would be a defective thermostat. When you turn on your AC, you would hear a click indicating that it’s on. But if you turned it on and it’s not operating, you will hear a continuous clicking sound.

Your AC is most likely forcing itself to turn on, but it can’t. This situation evolves from a broken capacitor. Your capacitor provides energy for your AC components. So, the unit will also force itself to operate even though there’s insufficient energy.


Sound #4. Hissing

This sound is one of the urgent ones. And you should turn off your AC immediately and call a technician. The hissing most likely comes from leaks. For example, there is a tear in the cables or ducts, and the refrigerant might be leaking.

Or one of the valves in your compressor is not sealed tightly, or there’s also a leak. The hissing noise might be produced by high pressure in certain places, which our air conditioner can’t handle.


Sound #5. Whistling

This noise would sound similar to the previous one. But it’s less high-pitched. And it could be caused by several factors such as clogged filters, leaks, and many more.  There is inadequate airflow if your air filter is coated in dust. It would also affect the performance of your blower motor.

Your motor will require more air, but it will forcefully perform that function because of limited airflow, and this would result in high pressure in your blower motor, which produces the whistling sound.

The air being forcefully absorbed through the blocked filters might also be causing the noise. It’s like whistling with your lips since there’s just a little passageway leading to the unit.


Sound #6. Cracking

Whenever your AC is low in freon, there will be ice particles forming in your condenser and pipes. So, if you hear a cracking sound, it should be the ice.

They tend to break if they’re too solid or if they became too heavy. And that breaking will produce this sound. And these sounds could explain why your air conditioner makes loud noise when starting.


Wrapping Up

And that concludes the article about why your air conditioner makes loud noise when starting. There are still other causes behind this phenomenon, but the mentioned sounds are the most common.

Despite the varying loudness of these sounds, you still have to get your AC checked and fixed by a professional. To avoid more complicated situations, you should be observant of your equipment and provide them efficient maintenance. Thank you!

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