Is your outside AC unit making loud noise? Well, that is a sign that you need AC repair.

Your outside air conditioner making some strange sounds is a sign of a malfunction. And, it would be ideal if you were on the move to find a solution as soon as you hear those weird noises.

We help you fix a noisy outside AC unit. But before we get there, you may want to know what the exact problem with the AC system is.

We look in detail at noise issues with the outdoor AC unit below.

What to do when outside air conditioner makes a loud noise

My outside AC unit is making a loud noise; what should I do?

First, switch off your AC unit.

Sometimes, the air conditioner is performing correctly despite the strange loud noises. And in such cases, many homeowners would be tempted to keep using it. After all, it is conditioning the indoor air properly.

If you keep running it with the noises, the harm will progress and destroy the entire unit or even your home. The damages will be much more expensive.

After switching it off, you will need to dial for AC repair technician .

However, if it is in the hot months of summer, you do not want to wait for long. You will need emergency AC repair.

But what do you tell your HVAC technician when you call them? How do you describe the noise? Let’s look in detail at the types of noises your outside AC unit could be making.

Types of Noises your Outside AC Could be Making and What They Mean

The kind of noise your outside AC unit is making would most likely indicate what the problem with your AC unit is.

We review in detail the types of noises your air conditioner could be making and their causes.

Banging Noise

Banging Noise in your AC often indicates a detached or broken part. These parts could be the:

• the crankshaft,
• connecting rod,
• piston pin,
• parts of the internal compressor,
• poorly balanced internal blower.

If a part in your air compressor is broken, you will need to get a new air conditioning installation or replacement rather than a repair.

Sometimes, your outside air conditioner’s banging or slamming noises are due to worn out springs. The compressor is supported by springs(1 ), which may give out sometimes. In this situation, the compressor loses balance and eventually slows down. This makes it hit the nearby parts, causing the banging noise.

The banging noises could also be caused by a condenser fan hitting against the unit. If there are loose parts on the condenser fan, they will hit on the outdoor unit, causing a loud banging noise.

If you hear loud slamming or banging noise, you need to call for HVAC repair services as fast as possible. Loose parts banging on other parts could cause more damage to the banged parts.

 Buzzing Noise

Is your outside AC unit making a loud buzzing noise?

A persistent loud buzzing noise is often due to an electrical issue in your air conditioner.

It most likely would be a damaged circuit breaker. This could be due to non-code compliant wiring or old age. 

The other issue could be a broken capacitor.

If you hear a buzzing noise, switch off the AC system immediately. It may otherwise cause damage or fires in your air conditioner or house.

You will need to call an experienced HVAC technician to diagnose the electrical problem and fix it.

Screeching Noises

Screeching noise from your outdoor AC unit sounds like metal grinding against metal.

When you hear screeching noises, the suspect would be:

• A malfunctioning condenser fan motor. You will see a large fan when you look into the top of your outdoor AC unit. If that fan fails, it will make a loud screeching noise while it operates.
• A broken compressor: The compressor is in charge of the circulation of the refrigerant. If the motor inside the AC compressor is starting to malfunction, it will sometimes make a loud screeching sound while the AC is functioning.

Screeching noise from your outside AC unit is often due to issues in the condenser. Many times, the condenser lasts 10 years. If you have had your condenser for more than 10 years and get the screeching noise, it is best to get replacement rather than repairs.

Popping Noise

The popping noise sounds like popcorn popping.

Please turn off your AC system when you hear it making a popping noise.

Popping noise is due to the compressor sucking up liquid refrigerant from the suction side.

Usually, when refrigerant absorbs heat from your indoors, it transforms into a warm gas. This warm gas is supposed to enter the outdoor compressor and not the cold liquid.

If the liquid refrigerant is entering your compressor, you need to get emergency AC repair. The compressor is one expensive part of your A unit. You do not want it to get destroyed and to have it entirely replaced.

Hissing Noise

A hissing noise is often due to a refrigerant leak.

Refrigerant circulates through copper wires in a closed loop. This implies that you should never run out of refrigerant. However, you may soon run out of it with its leaking refrigerant.

When refrigerant leaks from the copper lines, there will be a change in pressure. The pressure change is what causes the hissing noise. Think of this as air escaping a balloon.

Other signs may show refrigerant leak, but hissing AC noise is one.

Refrigerant is a highly toxic substance. This is why you need a professional to solve your refrigerant leaks.

Rattling or Chattering Noises

Chattering or rattling noises could be due to minor issues such as debris and small twigs in your HVAC system. This is common when you do not cover your outdoor unit during winter.

However, loud rattling noises could be due to loose parts in your outdoor unit. This could be a loose blower fan. There could also be electrical issues in the air conditioning units.

Your air conditioner is making rattling noise due to debris and small twigs. However, if you look inside the noisy air conditioner and see no debris, you need to call an AC technician.

Screaming or Whistling Noises

Screaming noises or high-pitched whistling Noise needs you to immediately cease your entire AC unit.

Let your HVAC technicians come and fix this problem before using your AC unit again. Screaming and whistling is often when refrigerant leaking is getting out of hand. However, it could often indicate that the refrigerant pressure in the refrigerant piping is dangerously high. This is why you need to turn the system off.

As already stated, this is detrimental to your air conditioning unit. Also, it is harmful to the residents of your home.

Also, over-pressurization on the compressor can cause a screaming sound.

Whirring Noise

Think of a whirring sound like the Noise you’ll hear when a helicopter flies over a building.

A whirring noise can often be an issue in your indoor or outdoor unit.

Whirring loud noises from your outdoor unit could be due to:

• ripped, torn or broken belt,
• loose or displaced belts hitting parts they should not be hitting,
• debris stuck in the fan motor.

Humming Noise

Humming noise is potentiality due to:

• loose parts or loose refrigerant piping,
• malfunctioning compressor,
• electrical issues such as loose wiring.

If you have loose refrigerant piping, you need quick AC technician intervention. Refrigerant issues can get out of hand real quick. Feel free to reach out to us in HVAC Santa Clarita when you hear humming noises in your AC.

 Pulsating Noise

If your air conditioner is making loud pulsating noise, you most likely have loose parts. It could also be due to malfunctioning parts needing repair or replacement.

When there is a pulsating noise, the parts that need attention include:

• fan motor,
• fan blades,
• unit panel.

If these problems are not solved quickly, they could become greater problems. Don’t hesitate to contact HVAC Santa Clarita if you hear any weird pulsating noises.

What to Do About Loud Noises from HVAC Outdoor Unit

When you hear loud bothersome noises from your outdoor unit, the first thing that should come to your mind is to get a solution.

If the problem is not fixed, it will persist and cause greater damage. This means that you will have to spend more on AC repairs. Dial for repairs as soon as you notice the problem.

Call HVAC Santa Clarita today for AC repairs.

However, you may want to look inside the outdoor unit. Debris and small twigs or leaves are problems you can fix. You can fix the rattling noise quickly by getting the debris out of the system.

We, however, discourage you from trying to fix other technical problems. Without the right expertise, you may damage the parts. You may also harm yourself while dealing with refrigerant leaks or loose wiring.

Therefore, if you notice that the problem is beyond debris, twigs, or leaves in the system, we encourage you to switch the system off and give us a call. We will diagnose the problem and professionally and safely fix it for you.

Making your Air Conditioner Quieter

Your outside and inside AC unit will always make low, steady noise. However, the Noise will be so low and will most likely fade into the background.

However, sometimes, the Noise is not just settling even if there is no problem. If you feel like you can’t take the regular AC noise from the beginning, feel free to talk to us at HVAC Santa Clarita. We will schedule an AC maintenance service to troubleshoot and ensure there is no problem with your system.

This is also when you notice your AC making a loud noise inside unit.

And if it is clear that there is no issue, we can offer you solutions such as:

• recommending a sound blanket to muffle AC noises,
• getting a sound dampening technology,
• having small plants around the outdoor unit (you need to ensure the plants don’t get so close)

When is it Time to Replace a Noisy Air Conditioner

Picture this:

Your AC is making loud buzzing noises today. You can use your HVAC technician, and they fix the buzzing sound. The following week, it is making a high pitched squealing noise. You need to call a technician to fix that again. The week after that, it is making…

If you are spending more on frequent repairs, the chances are high that your AC unit is old. Getting an air conditioning replacement can solve these problems once and for all. You do not want to keep wasting money on AC repairs of an outdoor system that is on the verge of dying.

Outdoor AC Making Noise Frequently Asked Questions

Here are some of the FAQs that surround a noisy outdoor unit. Hopefully, these answers any questions you might have. If not, feel free to give our professional HVAC team a call. We are always ready to answer your questions.

Meanwhile, let’s get into these FAQs.

Why is my Outdoor AC unit Making a Loud Noise?

There are many different reasons your outside AC unit could be making a loud noise. Depending on the type of noise, the problem could be:

• condenser fan motor or fan blade issues,
• loose AC parts,
• frozen air conditioners after running for too long,
• damaged compressor,
• destroyed belts,
• debris lurking in the system,
• issues with loose wiring and refrigerant piping,
• refrigerant leak.

The issue could most likely be one or a combination of these.

Why is my Outdoor Unit Making a loud Noise just when I Start or Shut it?

Sometimes, the outdoor unit makes loud noises just when you turn it on or off. There are several reasons behind loud Noise when you start your AC unit:

• debris in the HVAC system,
• loose fan,
• loose springs that can’t support the compressor, hitting the HVAC cage.

What Does a Normal AC Compressor Sound like?

Typically, there will be a low and steady blowing noise from your outside AC. This is because it is blowing the air. The noise often fades into the background, and you will barely hear it when you are indoors. However, if your outside AC’s Noise is no longer in the background, there is definitely an issue that needs to be solved.

What does a bad AC unit Compressor sound like?

There is likely a problem if your compressor is making noise other than the normal blowing sound. Noises that may indicate a problem include buzzing, screaming, banging or slamming, pulsating, whistling or hissing.

How do I stop my outside AC unit from making Noise?

If your outside AC is making a loud noise, you need to call an HVAC technician. They will have to diagnose the problem and repair it.

However, if you find your outside AC loud still after repairs, you may want to get a sound blanket to muffle the noise.

Final Thoughts on Outside AC Making Loud Noise

Time to call it a wrap for outside AC unit making loud noise.

We trust you know when to detect weird noises from your AC. And you certainly have a clue on what strange noises sound like.

To save yourself greater damage and more money on a replacement, shut down your AC as soon as you hear weird noises. Then, give us a call at HVAC Santa Clarita, and a professional HVAC technician will help you fix that problem.

A silent and well functioning HVAC system brings peace of mind and well-treated indoor air. Do not hesitate to call us as soon as you hear your outside AC making a loud noise.