Air Conditioner Makes Loud Noise When Starting – Fix It Easily

An air conditioner is an essential piece of furniture in most homes, and for good reason. It’s essential for keeping a room cool during the summer months, and even in the winter, it can keep you comfortable. Air conditioners are present in over 100 million American homes. That alone tells you the number of people that potentially face air conditioner issues. But what do they do when the air conditioner makes loud noise when starting?

Do they live with it? Of course not. That could be irritating. You guessed it; they find solutions. And what could be the potential solutions to that? You’re about to find out how to stop that. Let’s get on with it right away.

Is it normal for AC to make noise?

Some people may think that it is abnormal for an air conditioning unit to make any noise, but in reality, most AC units produce some kind of noise. This type of noise can vary depending on the model and age of the AC unit, but in general, it can include clicking, whirring, or buzzing noises. While this may be annoying at times, it is generally not a sign of a problem.

What Noises Does An Air Conditioner Make?

When your air conditioner kicks on, it creates a special refrigerant gas (compressor agent) that gets pumped to the roof, where it’s dropped into a cooling coil. This cycle repeatedly happens so that you can keep your home cool throughout the season.

But what if this sound isn’t normal? Your air conditioner might make sounds that don’t seem to fit your air conditioning cycle. 

You can either hear the fan going but not much else or maybe even some rattling in the machine. If this is happening consistently, it could indicate that there is something wrong with your system. 

Some parts of an air conditioner are noisier than others, and it’s essential to know the difference between normal and abnormal sounds. Here are some things you might hear with your unit:

  • Grinding/Clicking Sounds

Slight grinding noises typically mean that your compressor is working correctly. These may be hard to hear when you’re in another room, but that’s a big problem if they stop entirely.

Clicking noises are your condenser fan at work. It produces such sounds as it cools or heats the system’s components and attached ductwork. Most times, you can hear this sound from other rooms if the fan is working hard.

The problem comes in when you hear this clicking sound as you turn the air conditioner on. That will most likely point to electrical issues.

How to Fix It: Consult an HVAC professional. Attempting to repair it yourself could leave you with more losses as you might damage the AC.

  • Banging/Gurgling Sounds

If you hear loud banging or gurgling sounds when you start the AC, the outdoor coil may be full of water. You might also notice a puddle outside your unit if this happens. This problem can develop because dirt is clogging the drain line or the condensation pump has stopped working.

Sometimes you might notice a gurgling or pulsating sound whenever you start your AC. That could be because there is a collapsed or broken-down drain line. The collapsing creates a vacuum in the unit and will cause water to bubble or gurgle.

How to Fix It: drain the coil of the water that might clog it up. It is usual for the condensation to build up here. Therefore, draining it will stop the gurgling and banging sound.

  • Humming/Buzzing Sounds

A humming or buzzing sound may result from a problem with the Contactor (the part that controls your compressor).

How to Fix It: If you hear this, have a professional inspect your system to ensure everything’s working correctly. You might need to replace the contactor if it’s malfunctioning or causing your system to trip.

  • Whistling Sound

A whistling sound almost always results from a faulty outdoor coil. That can happen when the refrigerant isn’t flowing correctly through the unit, and the air gets trapped in pockets of insulation between pipes. As that air heats up, it expands and becomes an obstruction for cool liquid nearby.

How to Fix It: Get an HVAC technician to examine the air conditioner and solve the problem.

  • Loud Buzzing/Humming Sound

This is a common issue with most air conditioners, but it doesn’t necessarily mean that something is wrong, per se. The noise comes from a fan inside the unit called a condenser fan. It has to operate at all times to pull heat from your home and exhaust it outside.

  • Loud Buzzing/Humming AND Odor/Vapor Release 

Although this section is somewhat of a gray area, we’re including it because these two issues can be related. When you have a condenser fan running at all times, but there are still loud noises emanating from your unit, there’s a good chance it is leaking. 

Since these problems can be costly to repair, a technician should evaluate them and let you know if they could fix them cheaply or expensively. In most cases, we recommend having your unit professionally inspected before making any hasty decisions.

Read Also: Air Conditioner Starts Then Stops After Only a Few Seconds – 8 Effective Solutions

Why Does Your Air Conditioner Make a Loud Noise When Starting?

Before you can understand how to correct the issues, you first need to know the potential causes. Why would a perfectly okay air conditioner make noises each time you start it?

If your Condenser fan is not hooked up properly to the compressor, there will be a noise each time the fan moves. The noise will be more prominent when you start the AC and the fan begins powering up.

Another reason you might hear a loud noise when you start your AC is that the equipment’s pressure switch is malfunctioning. There is only one solution for this, and that is to replace it.

Although rare, there are times a gasket or seal on your outdoor unit has an issue that makes it produce a loud sound when you start it. That will also need replacing.

It all boils down to the air conditioner having issues in operation or some parts. That’s why it makes a loud noise whenever you turn it on. Most of these sounds you can fix yourself. For example, you could drain the drain plug if you hear a gurgling sound.

Some issues, however, will require you to get the help of a professional HVAC technician. Attempting to solve the problems yourself might only make it worse.

With that out of the way, let’s look at some other common fixes you can do to ensure your air conditioner isn’t making too much noise when you start it.

Common Do It Yourself Fixes for Loud ACs

It is not always the Ac will make noise when starting. Some do make noise even when in operation. Most of the solutions we have mentioned so far have required you to call an HVAC professional. These, however, won’t need you to call a pro as you can easily do them yourself. 

  • Lubricate the AC Motor

An unlubricated motor will produce loud grinding noises whenever the AC is in use. Such noises can be pretty irritating, which is why you need to fix them by lubricating the motor.

Oiling the motor will help reduce such noises and have your AC working silently. You could do this each time summer arrives.

  • Install Noise-Reducing Barrier

If you want to lower the noise from loud AC, you will need to install noise filters, a noise barrier, or simply a quiet fence. You can use these devices to reduce the discomfort caused by loud air conditioners.

  • Loose Screws Need Tightening

Loose screws in any machine will be responsible for loud rattling sounds. That’s why it’s a good idea to examine the screws each time you have rattling sounds from your AC. Tightening these screws will help get rid of the noise.

The screws hold several parts, like the fan or blade. When loose, they can cause loud rattling sounds. These sounds might occur when the air conditioner is starting or even when it is running.

  • Clean the AC fans

Dirty fans are another significant cause of noise in Air conditioners. That’s why regular cleaning should be a part of your maintenance schedule. You will need to open the AC to know if it’s the dirt causing any issues.

If you find any debris inside the fan or other parts of the AC, clean them and remove the dirt inside. A soft cleaning brush will often come in handy here.

Another part of the Ac to give special attention are the coil fins. If this gets dirty, then the AC will also produce noise when starting and running. Check it and clean it if it has any dirt.

  • Arrange Regular inspections

Regular inspections can help detect problems before they occur. Any flaws in the system can be identified by an HVAC professional, who can also recommend necessary repairs.
Schedule a maintenance inspection once or twice a year to keep your HVAC in good working order.

Frequently Asked Questions

How do you fix a noisy air conditioner?

A noisy air conditioner will require you to examine all its parts for issues and fix them. If it has loose screws, tighten them, dirty fans, and clean them. Some other times the noise won’t be that loud and will be the fan working.

Do quieter air conditioners exist?

 Yes, certain types of air conditioners are way quieter than others. That’s because they use sound dampeners that ensure they aren’t as loud as traditional air conditioners.

If you can’t stand the noise from your current air conditioner, getting a quieter one should help.

What are the symptoms of a bad AC compressor?

If your AC compressor is not running properly, it could be causing some pretty serious symptoms. Here are some of the most common ones:

1) Suffocating Humidity: If your AC isn’t working properly, it won’t be able to send enough air to cool down your home in hot weather. This can cause high humidity levels, which can make you feel like you’re suffocating.

2) Noisy Air Conditioning: A bad AC compressor can also cause lots of noise when it’s working. This is because the unit is trying to create a lot of pressure and winds up making a lot of noise as a result.

3) Poor Air Quality: If your AC compressor isn’t working well, it will likely produce poorer-quality air than usual.

Is all noise from an air conditioner an issue with the machine?

No, not all noise is because the air conditioner has an issue. Some sounds are normal operational sounds. For instance, if the air conditioner might produce a slow humming sound that merely shows that it is working right.

Let’s Wrap Up!

We hope you know what to do when your air conditioner makes loud noise when starting. Apply the fixes we have mentioned here, and you will have a much quieter air conditioner cooling up your house.


Relevant Resources:

    1. How to Seal a Window Air Conditioner for the Winter – 6 Easy Steps
    2. Can You Use a Window Air Conditioner Without a Window
    3. Can I Run AC Without Filter – Learn From Experts
    4. Frigidaire Air Conditioner Buttons Not Working – Fix It Now
    5. 7 Reasons Portable Air Conditioner Compressor Keeps Shutting Off – Solutions
    6. How Can a Portable AC be Used as a Dehumidifier – 3 Best Steps