My Air Conditioner Is Loud/Noisy, What’s Wrong? A Phoenix Tech Explains

Air conditioners have a lot of moving parts (like motors and fans) that tend to make noise. So, if you hear your AC system startup or you can hear it softly running, there’s nothing to be concerned about.

However, if you notice that your AC is suddenly louder than normal or is making the following noises, there’s likely an issue.

If your AC is making a...

...there’s an issue with your AC system.

Below, we’ll look at each of these noises in more detail so you can get a better understanding of what’s causing the noise and what steps you need to take to prevent long-term damage to your AC system.

A buzzing noise usually indicates some sort of electrical issue such as:

• A circuit breaker that is failing to trip
• Bad capacitor
• Loose wiring

Let’s look at each of these issues in a little more detail:

A circuit breaker that is failing to trip- If there’s an issue with your circuit breaker, it can allow too much current to flow through the wiring, which can make a buzzing noise. Working with wiring and circuit breakers can be dangerous, so if you think this may be your issue, you’ll need to reach out to a professional for help.

Bad capacitor- A capacitor is like a large battery in your outdoor unit that helps your AC system startup. But, over time, the capacitor can go bad and cause a buzzing noise (if your capacitor is bad, this buzzing noise will only be audible near your outdoor unit). If your capacitor is bad, you may also hear some clicking noises, which indicate that your AC is trying to start up. If you think a bad capacitor maybe your issue, you’ll need to reach out to a professional to replace the capacitor.

Loose wiring- Another reason you may be hearing a buzzing noise from your AC system is a loose wire. If a wire is damaged or isn’t properly connected to the circuit breaker, it can make a buzzing noise. Obviously, a loose wire is not good news, and you’ll want to reach out to a professional who can repair it asap.

Need more info? Check out our blog, “Why Does My Circuit Breaker Panel Make a Buzzing/Humming Noise When My AC Comes On?”

If you hear a rattling noise in your indoor or outdoor unit, there could be a few issues, like:

• Debris has fallen into your outdoor unit
• A part is loose either in your indoor or outdoor unit

Let’s look at each of these in a little more detail.

If the noise is coming from your outdoor unit…

• The most likely reason is that some debris, like small rocks, a stick, or some other kind of brush fell into your outdoor unit. Your fan could be hitting this debris and making a rattling noise. If you look into your outdoor unit and see debris, you’ll want to contact a professional as soon as you can. Debris that’s left in your outdoor unit can damage the internal parts, like the fan, so you'll want to remove the debris immediately.

• There could be a loose part in your outdoor unit. For example, if your refrigerant pump is loose, it can rattle around in your unit when your AC is on.

If the noise is coming from your indoor unit…

You likely have a loose part. The same methodology applies here as it does with the outdoor unit. If a part is loose, it can rattle around when the AC is on. Since the indoor unit is typically less accessible than the outdoor unit, it’s safe to say that no matter what part is loose, you’ll want to reach out to a professional for help.

Want to learn more? Read our blog, “Why is My Air Conditioner Making a Rattling Noise? A Phoenix Tech Answers”

Both your inside and outside AC units have fan motors.

If you hear a grinding noise, that likely means the fan motor bearings are bad or need lubrication.

If you think this is your issue, you’ll need to contact a pro to lubricate your fan bearings or make any necessary repairs if your fan is damaged. To prevent this issue in the future, make sure to schedule annual AC maintenance. During a typical AC maintenance visit, a professional will typically lubricate all AC motor bearings (among many other things).

If you hear a squeaking noise, the most likely cause is a loose fan belt in the indoor unit. This can happen if the fan belt has come off the track or if it’s just damaged or frayed due to old age.

To fix this problem, you’ll need to contact a pro to come to take a look at your system and potentially realign the belt or replace it.

To prevent this issue in the future, you should invest in annual maintenance.

If you hear a hissing or bubbling noise and your AC isn’t cooling your home well, then you probably have a refrigerant leak. The hissing noise is the refrigerant escaping the leak and the bubbling noise is from air that has made its way into the refrigerant lines.

If you hear a hissing or bubbling noise, a professional technician needs to fix the leak ASAP. If your AC gets too low on refrigerant, the compressor can become damaged.

Looking for more info? You can learn more on our blog, “Why Is My Home’s AC Hissing? An AZ Tech Answers”