Does your air conditioner sound louder than usual? While a loud air conditioner can be irritating, it can also be helpful — an air conditioner making loud or unusual sounds likely has something wrong with it, and understanding that noise will help you locate and fix the issue. Learn about different air conditioner noises below to narrow down why your AC unit is so loud.

What Causes Screeching and Squealing Noises?

If you hear a high-pitched squealing or screeching noise coming from your AC unit, it could mean:

1. Fan Motor Fault

The screeching noise you hear might be metal scratching against metal. This occurrence suggests that your fan motor bearing might be faulty or worn out. It can also mean dirt and dust have accumulated over time, interfering with the smooth operation of the bearings.

This issue is best solved through cleaning and lubricating the bearings, which an air conditioner technician can do for you. After cleaning your fan motor, a professional will use oil, grease or specialized metal lubricants to service it. If that approach doesn't work, it may be time to have them replace your bearings to get rid of the screeching noise and get your AC unit back in working order.

2. Broken Belt

A common source of squealing noises comes from worn-out or broken belts. These components are used in older AC system models, which can wear over time. Additionally, high levels of humidity can cause the metal of the belt to contract and expand, which makes an unpleasant squealing noise. Having a professional quickly replace the worn-out or broken belt is the best solution.

3. Pressure Buildup in Compressor Unit

In some cases, high-pitched squealing coming from your AC unit could mean a lot of pressure has built up in the compressor unit. This pressure buildup could be dangerous, so you should contact a professional for emergency repair as quickly as possible.

What Causes Banging or Rattling Noises?

If your AC system is making a rattling noise, three possible issues could be the reason:

1. Dirty Condenser

Keep in mind that loud banging and rattling noises don't mean your air conditioner needs replacing. Those sounds could just indicate that dirt particles or debris are stuck in your condenser. Objects like sticks, dust, leaves and dirt often get sucked into the condenser, causing these noises.

A professional can take off the condenser cover, inspect it to see if that's the problem and clean out any dirt or large items that have been stuck inside.

2. Loose Screws

Loose screws are typically the cause of rattling noises. Most air conditioners vibrate when turned on. If any screws are loose, the vibrations will create a rattling noise. You can check around the outside of your AC unit to find loose screws or panels, which the screws attach to the unit. Tighten the screws with a screwdriver to secure everything and solve this problem.

3. Broken Compressor or Fan Motor

In the worst-case scenario, the banging noise is coming from a damaged fan motor or compressor. If either of those parts is broken, your air conditioner will make a loud banging sound when you turn it on.

Replacing these parts is the only way to make the banging and rattling noises stop. Have a professional do a thorough inspection of your AC unit to determine the problem before you take any other steps. This way, you can assess whether you just need to replace the broken parts, or if it would be more cost-effective to replace your entire AC unit based on its age and condition.

What Causes Buzzing Noises?

When your AC unit is making buzzing noises inside your house, you should check for the following issues:

1. Malfunctioning Parts

There are three malfunctions you should look for when your air conditioning unit is making a buzzing noise — a malfunctioning compressor, a faulty motor or a worn-out capacitor.

When you hear an air conditioner's compressor make a noise, it's likely broken — and if the unit is still getting power even after the compressor stops working, it will produce a buzzing sound. A technician will need to replace the compressor to stop the buzzing.

A faulty motor will also cause buzzing sounds. It can also happen when obstructions are near the copper lines that connect to your unit. When copper lines rub together, they will produce a dull buzzing noise. Have a professional ensure the lines are properly insulated and prevent as much metal-on-metal contact as possible.

When a capacitor breaks down, it will stop the fan from turning on. The friction will cause the buzzing sounds. You will need an AC technician to come and help you repair or replace your capacitor.

2. Wiring Difficulties

An air conditioner's contactor controls the flow of electricity to the unit's compressor. When it malfunctions or wears out, it might prevent power from getting to the compressor. A loud buzzing sound will come from your unit when it tries to start up but can't due to contactor problems. Get an air conditioner technician to help you fix any contactor errors.

What Causes Humming Noises?

Your air conditioner will always make a soft humming noise. However, when it makes a loud humming sound, that's a sign something might be wrong.

1. Lack of Lubrication

For your air conditioner motor to emit a normal humming sound, it needs proper lubrication. When your motor is running low on lubrication, that dull hum it makes will quickly become a loud grinding noise. Reach out to a professional, so they can service your AC unit, locate the issue and apply lubrication if necessary.

2. Bent Fin Coils

The fin coils keep warm air away from your AC unit while it's running. When these coils are bent, they produce a strange humming noise. A professional can straighten any bent coils to eliminate the sound and help your AC unit stay operational. You can prevent this issue from happening with regular HVAC maintenance services.

Keep Your AC Unit Sounding Normal With Boss Mechanical

If your air conditioner is making noise and you can't figure out what's wrong, give Boss Mechanical a call. Our licensed technicians will come by to figure out and fix the problem, so you can get back to using your unit as usual. Additionally, we can make sure your system is functioning perfectly all year long with our maintenance services. Scheduling regular services can help you avoid broken parts and strange AC unit noises altogether.

Whether you want your HVAC systems maintained or fixed, or you're interested in upgrading to a new air conditioning unit, we are your go-to contact. Contact us any time to find out more about our services and schedule a service today.

Air Conditioner Noises: What Causes Them and How to Fix Them