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Why Is My Air Conditioner Making Noises

Woman Holding Remote Control Aimed At The Air Conditioner

Do you know that your air conditioner alone is responsible for 17% of your electricity bill? That’s huge.

But what if you’re paying off the bills only to hear cranky noises from your air conditioner? Not cool! Therefore, we’re here to help you out if you’re still thinking, why is my air conditioner making noises?

These days, air conditioners include quiet motors that can be adjusted to run at two speeds. However, there might be a serious problem if you hear a loud and intrusive noise from your air conditioner.

These noises frequently indicate that your system needs to be repaired or replaced.


Depending on the type of air conditioner you have, modern HVAC systems use a sound-dampening technology to limit the noise level between 25-55 decibels.

However, the main reason your air conditioner is making noises is the deterioration. Other than this, high-pitched squealing noises are caused by a slipping belt or a motor problem with the condenser fan’s bearing.

The deterioration of air conditioners over time is due to wear, which results in holes and splits.

Nevertheless, the good news is the majority of these noises can be fixed during routine maintenance.

Also, it can be done as a DIY project without any technical assistance.

But before hopping to the fixes, you first need to understand what type of noises your air conditioner is making to understand the problem better. So, here’s the list of all the sounds your air conditioner could make and the potential issues they indicate:

Types of Noises and Their Causes

The first step in fixing your noisy air conditioner is to find out where the noise is coming from. You can get a good idea of what’s wrong with the air conditioner and how to fix it by listening to its noises.

1. Rattling or Banging Noise From AC

Asian Woman Feel Annoyed And She Is Suffering Noise From Heating At Home

A rattling or banging noise from your AC might be due to your air conditioner’s condenser malfunctioning. However, this might only sometimes be the case.

Some other causes of this noise are the accumulation of dirt particles in the condenser.

Tiny twigs and leaves can become lodged in the condenser if you place them outside, plants surround your condenser, and you only clean it occasionally.

To get rid of stuck objects, remove the condenser cover. If operating your HVAC system seems difficult, consider hiring a professional.

Additionally, a lot of rattling sounds are caused by loose screws.

An air conditioner, including the inside and outdoor units, vibrates when turned on. The screw may eventually go loose due to this vibration. To fix this, you only need to use a screwdriver to tighten the screws.

2. Pulsing Noise From AC

Upset Man While At Home With Ac Unit

The steady pulsing sounds coming from your air conditioner may be completely normal. A problem, however, is indicated if the noise is both loud and rhythmic.

The primary cause of pulsating noise is an unstable blade or fan coil. It might originate from a coil or a fan blade that has become loose over time and is the source of the AC noise.

Your AC will quickly return to normal if you merely tighten the screws.

If a plastic base supports your air conditioner, the motion of the compressor may cause both the base and the entire unit to pulse.

Consider using a wooden cushion instead of the plastic one to avoid this issue and reduce vibrations. The unit can be securely clamped to the pad and supported on tiny rubber blocks.

3. Squeaking and Screeching Noise From AC

Air Conditioner (Ac) Wall Mount Or Indoor Unit Of Split System For Control Climate

Are you hearing a high-pitched shrieking or squealing sound from your noisy air conditioner? This could be for several reasons for this. For instance, when you switch on your air conditioner, a metal-on-metal screeching sound indicates that the fan motor bearings need to be replaced.

On the other hand, squealing sounds can also be produced by a broken or worn-out belt, such as a fan belt.

The most common source of this noise is ducted or central air conditioners. An old-fashioned model’s motor and fan are connected by a belt that eventually wears out.

Furthermore, the belt may compress and expand throughout the summer due to the high humidity, which may produce unpleasant noise.

However, if you need the belt repaired or replaced, contact a reputable HVAC company.

Furthermore, when your air conditioner makes, chances are considerable pressure jas built up in the compressor.

As a result of significant pressure buildup, immediately turn off the air conditioning system.

4. Hissing Noise From AC

Young Woman Looking At Technician Examining Air Conditioner With Digital Multimeter

When your air conditioner keeps making loud hissing noises, have you ever had the strangest feeling that a snake has cracked your front door? However, never mind. The hissing sound can be from your faulty air conditioner.

A refrigerant leak is one of the causes of the hissing noise. The refrigerant line may have been damaged, which is why there is a leak in the system.

The lines may weaken with use over time, leading to leakage. Unfortunately, there is no do-it-yourself fix for this issue. Therefore, you would need to call a specialist.


A compressor valve leak may also cause hissing sounds. The valves regulate how much-pressurized refrigerant is introduced.

In this situation, you should speak with an HVAC expert because the problem could cause significant harm.

After some time, if the hissing sound seems to have changed into a screeching sound, there is a compressor problem.

Your outside AC unit may have accumulated high pressure. Therefore, shut off your air conditioner and immediately call a technician to look into this problem.

5. Humming Noise From AC

Modern Air Conditioner Unit Service

It’s not unusual for its motor to emit a gentle humming sound, but when it becomes loud, it raises suspicion. Your air conditioner might be whistling if an electric motor is low on oil.

However, if you keep using it without addressing the problem, it will start to make a loud grinding sound.

Another reason for the humming noise can be contractor error. The contractor is in charge of managing the electricity supply to your air conditioner.

When you turn off the air conditioner, the contactor opens, cutting off the power supply. As soon as you flip the switch on, things return to normal, and power is restored.

Your air conditioner makes humming noises when the contactor fails because it receives power but cannot switch on.

If you continue to overlook the problem, it can soon start to buzz inaudibly.

6. Whirling Sound

Air Conditioner On The Wall Of The Room

If your air conditioner makes helicopter-like noises, it may be experiencing any number of technical issues, either with the internal blower or the exterior unit.

An air conditioner’s whirling is typically caused by malfunctioning fans outside or inside the blower unit or by damaged bearings in the motor driving the indoor blower fan.

An air conditioner can produce an irritating whirring sound if the fan blades become dislodged or the fan itself breaks down.

Make sure to contact a specialist if there appears to be a mechanical problem.

Anyplace in the system where a belt is utilized could have a broken or worn belt, or the interior blower fan or outdoor fan unit could have a piece of paper or debris stuck in it, causing the fan to whir.

Clean the unit’s interior with a hose and a soft-bristled brush if debris appears to be the root of the whirring sound.

Why Should You Pay Attention to AC Noises?

Air Conditioner In The Room

Your air conditioner may have a problem if it makes strange noises or gives out odors. Neglecting unexpected noises emanating from your HVAC system can escalate little problems into long-term problems that could harm your system’s health.

Tax systems from leaking refrigerants, audible as a bubbling noise, can be inhaled by humans. So it’s important to avoid any noise problems as soon as possible.

Furthermore, disregarding the noise problem might lead to expensive costs that can be avoided. For the best overall functioning of your equipment, try to identify the noise’s root source noise’s as possible and fix it.

Carefully maintaining your air conditioner and cleaning it regularly can help stop the air conditioner from making odd noises.

However, even in that case, it’s still best to identify the root of the problem as soon as possible. You can save money on future costly repairs by taking care of this issue right away.

Air Conditioner Noises in a Nutshell

Air conditioners should give you peace of mind, not a headache with weird noises. Therefore, identifying the root cause of the noise is the first step toward fixing it.

Probable reasons your air conditioner is making noises are a malfunctioning condenser, a clogged outside unit, or a malfunctioning fan belt.

However, you can easily fix these issues as a DIY project. Meanwhile, some cases require a technician’s assistance.

Frequently Asked Questions

Should I Shut Off My Air Conditioner if It’s Making Noise?

Your air conditioner makes a high-pitched screeching noise; considerable pressure has built up in the compressor.

As a result of significant pressure buildup, you should immediately turn off the air conditioning system to save yourself and your loved ones from damage.

What Noise Does a Failed AC Compressor Make?

Compressors with loose or out-of-balance parts may make a clanking noise, which, if ignored, could develop into a loud banging.

Besides this, if your outside unit makes a high-pitched squealing sound, your compressor system probably has a motor issue.

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