9 Reasons Why Your AC is So Loud + How to Fix

Air conditionersr is designed to stay quiet. But like any other piece of equipment with various parts that work in combination, you can run into some issues.

If your AC is so loud it might be because: part that’s broken, detached, or faulty. These issues produce different noises such as rattling, hissing, squealing, grinding, buzzing, whistling, clicking, humming and banging.

Read on to learn more about why your air conditioner is so loud, the easiest way to identify the cause, and how you can fix it. 

9 Reasons Why Your Air Conditioner is So Loud

Here’s why your ac is so loud:

1. Banging or Thumping Noise

Banging noises from your ac often occur when a part has detached or broken from your ac system.

To be more precise, these are parts of your AC’s compressor, including the piston pin, connecting rod, or crankshaft.

It can also be any other disconnected or snapped internal component of your compressor. 

Sometimes banging may occur when a poorly-balanced internal blower is functioning.

Note, the compressor is designed so that you should not disassemble any part from the unit, leaving you no option other than to replace it.

2. Rattling Noise

Don’t worry too much about a rattling noise coming from your ac unit. Often, this is nothing serious and may be due to any of the following:

  • A loose panel or part within your ac unit.
  • Loose or misaligned fan blades.
  • Debris in your outdoor unit—brushes, sticks, rocks, branches, or leaves.

A quick fix should solve the issue. 

First, check to ensure that all the screws and bolts are in place and fit snugly. Also, consider cleaning the condenser coil and changing the air filter.

It’s worth mentioning that consulting an HVAC technician is a smart idea as the expert will identify the problem precisely and fix it.

3. Hissing Noise

Be wary of a loud hissing noise when you turn on your air conditioner. It may indicate refrigerant line leaks.

Once the refrigerant is in a gaseous state or air seeps through that leak, a hissing noise comes out.

Other signs indicating a refrigerant leak are:

  • Sudden unexplained increase of your energy bill.
  • An AC that turns on multiple times than usual or works longer. 

Sometimes, the noise may be due to a malfunctioning valve or a leak within your home’s ductwork.

The best way to solve the issue is to call an HVAC technician. They’ll inspect your AC for the source of the sound, mend the leak, and recharge your AC.

Refrigerant is a toxic substance you should not handle by yourself.

4. Buzzing Noise

A buzzing noise coming from your air conditioner is one of the toughest to diagnose. 

While it might be something minor that a simple patch-up should solve, such as changing your air filter, it could also be more serious.

It may result from electrical issues within your ac unit, including:

  • A circuit breaker that’s not tripping.
  • A loose or damaged wire (poorly connected to the circuit breaker).
  • A damaged capacity, although this only requires replacing.

An obstruction near the copper lines connected to your AC unit may also produce a loud buzzing sound.

It’s advisable to turn off your air conditioner after you experience a buzzing noise. Then, call an HVAC technician immediately to assess the situation. 

5. Whistling/Rushing Noise

A whistling or rushing noise might indicate a problem with your duct, particularly undersized or poorly designed ducts

If the ducts have numerous sharp bends or angles (or they’re undersized), air velocity in the duct increases.

The result is a louder noise. A whistling noise often comes from the vents and may also be due to the duct design pushing excess air through them.

The following may also indicate duct issues: 

  • Mold growth on the vents
  • Stuffy air
  • Doors are slamming by themselves.

If your ductwork is damaged, have it fixed as soon as possible as it can affect your entire air conditioner.

Due to operational inefficiency, it will also cause a significant increase in your utility bill. 

A licensed HVAC technician will determine whether you need a quick repair or a redesign of your ductwork.

6. Grinding/ Screeching Noise

A screeching or grinding noise coming from your air conditioner might be a sign of a malfunctioning blower motor or one about to.

A loud grinding noise, especially from the outside, might also indicate:

  • A broken or misaligned fan blade
  • A falling compressor.

If your AC motor is faulty, your fan will stop functioning.

As a result, it’ll be impossible to rid your home of warm air.

Similarly, a poor or damaged compressor can produce a screeching noise. This is especially so if you’ve had your air conditioner for more than ten years.

A broken or misaligned fan blade in your outdoor unit can hit the inside in the process of moving, making a grinding or screeching noise.

Once again, a professional technician will diagnose the issue and repair any blower motor, motor, compressor, or fan blade.

7. Squealing Noise

If you experience loud squealing noise from your indoor unit, it’s probably due to a damaged blower motor.

If the noise is coming from the outside, it may be due to a worn-out fan motor

These damaged ac parts cause squealing noise throughout the duct system because of degrading efficiency.

Another cause of squealing is a damaged blower or housing wheels.

It’s worth mentioning that some units produce a low squealing sound during their regular operation.

Therefore, listen keenly to the sound to determine its nature. If it’s an irregular one, don’t hesitate to call an HVAC technician.

8. Clicking Noise

A click when you turn on your ac unit or when it turns off is no cause for alarm.

However, if you notice continuous clicking sounds, it means something is wrong. It might be a damaged compressor, an obstruction, or an electrical issue.

Clicking may also be due to a failing thermostat or faulty ac unit controls, indicating electrical problems.

Since this may accelerate the rate at which your unit wears down and even more dangerous situations, it’s advisable to address perpetual clicking noise instantly.

Regular air conditioner maintenance comes in handy in preventing loud clicking noises.

9. Humming Noise

It’s normal for your AC unit to produce a humming noise. However, a loud hum indicates something’s wrong. It could be bent fan blades, a falling fan motor, or even worn-out components. In addition, loose refrigerant piping can cause vibrations within your unit, producing a humming noise.

Humming can also result from electrical issues such as a malfunctioning compressor or loose wiring.

It’s crucial to address the issue immediately to prevent it from escalating into bigger problems. Sometimes, all that’s needed is to clean your fan blades.

But if the issue persists, call an HVAC technician to diagnose the problem.

When Should You Replace Your Air Conditioner?

An old ac unit may get loud due to worn-out parts. If your equipment is 10+ years old, consider replacing it with a new one. It will cost you a lot to repair an old AC/

For instance, if you’re still using an older unit that uses R22 refrigerant, restocking it might be challenging. For one, newer units use R410-A, and you cannot use the two interchangeably. Also, the old refrigerant is hard to come by. 

Another situation where you should consider replacing your ac unit is when your compressor gets faulty.

Replacing such a compressor is likely to cost you more than investing in a new air conditioner. Remember, in addition to less noise, a new unit is more energy-efficient, saving you money.

Final Thoughts

Every homeowner desires a quiet air conditioner that operates with no noise.

Nonetheless, noise issues arise with age, and once your equipment gets so loud, you have no choice but to address the issue.

It’s best to do this promptly. If you wait, the cost of repair might increase.

If you experience loud noise from your ac unit, contact an HVAC technician. An expert is your best bet at diagnosing the problem and fixing it. If your AC smells or is leaking, you can utilize our guides to fix your problem.

If you’re tired of your noisy AC, you can check out the best quietest wall air conditioners to replace your current one.

Image Credit: Flickr.com

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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