Air Conditioner Noises: What Are They? & How Can We Fix It?

Modern HVAC units have sound-dampening technology. This technology keeps the sound level between 25 to 55 decibels, depending on which type of air conditioner you have. Simply put, 25 decibels equals a whisper, and 55 decibels equals a normal conversation at home. Mini-split and window ACs are quieter than central ducted systems. If your AC makes unusually loud or strange noises, there is likely a problem. Although annoying, AC noises can be a sign that something is wrong.

Sometimes different problems can lead to the same type of noise. It is important to understand what these noises could mean.

To help you identify the problem and provide information on how to fix it, we have created a comprehensive list of AC noises that you may encounter.

• 1 - AC makes a rattling or banging noise

Your AC may sound like aggressive banging, but it may not be a condenser problem. These are possible causes and solutions for this frightening noise.

• Dirt particles in your condenser

It is possible to fix the banging or rattling noise from your air conditioner. This noise can be caused by dirt particles, leaves, or sticks getting stuck in the condenser. You should clean your condenser every once in a while if shrubs surround your outside unit.

To remove stuck items, take off the condenser cap. You may need to call a professional if you have difficulty handling your HVAC unit.

• Loose screws:

Also, loose screws can cause rattling sounds. When an air conditioner is turned on, both the inside and exterior units vibrate. This vibration can lead to the loosening of screws over time.

• Broken fan motor or compressor

If your air conditioner starts making a loud banging sound, it could be the worst-case scenario. A broken compressor could cause it. It can be very expensive to replace a compressor. It is better to replace your compressor when it has been more than ten years is a good guide to the life expectancy of air conditioners.

A broken fan motor or an unbalanced motor could cause loud bangs from your AC it will be expensive to replace the motor so consult a specialist.

You can have your HVAC compressor repaired if it has a lifetime warranty will save you the cost of labor a qualified HVAC technician will best be able to diagnose the cause of your problem and determine if repair or replacement is necessary.

2. Screeching & Squealing AC Noises

Do you hear a loud screeching sound or squealing sound from your air conditioner? There are many reasons this could be:

• Faulty fan motor bearings

If your AC makes metal-on-metal creaking noises when it turns on, the fan motor bearings are faulty and must be replaced.

• Belt Broken or Worn Out

Squealing noises can also be caused by a worn fan belt or broken belt. This noise is more common in central air conditioners. The belt connecting the motor to the fan in older models can wear over time. The belt can also expand and contract in summer due to high humidity, leading to unpleasant sounds. For repairs or replacement of the belt, contact a qualified HVAC company.

• High Pressure in the Compressor Unit

High-pressure buildup in your compressor can cause a loud, high-pitched sounding AC. High-pressure buildup can cause explosions. Get in touch with an HVAC professional as soon you can.

3. AC making a pulsating noise

Your air conditioner might be making slow, pulsating sounds that are not alarming. If the noise becomes loud and repetitive, however, it could be a sign of a problem.

• Loose fan blade or coil

A loose fan blade or coil could cause it over time. Tighten the screws, and your AC will return to normal within minutes.

• AC Plastic Base Pulsating

A plastic base that supports your AC can cause it to vibrate can avoid this problem by replacing the plastic pad with one made of wood to reduce vibrations. You can do this by clamping down the unit on the pad and supporting it with small rubber blocks.

• Refrigerant lines coming in contact with the AC Walls

Refrigerant lines touching walls can also make a pulsating sound. You can move the refrigerant lines slightly away from the wall to add insulation with rubber or foam material.

4. AC making a hissing sound

Do you ever feel like a snake has settled inside your air conditioner? Do you hear loud hissing sounds? These are possible causes:

• Leaking Refrigerant

A refrigerant leak could be the reason for the hissing sound. Damage to the refrigerant lines can cause leakage. The lines can become brittle over time, leading to leakage. This problem is not something you can fix yourself.

• Compressor Valve Leak

The compressor valve can leak and cause a hissing sound. The valves regulate the refrigerant's pressure is why you need to contact an HVAC specialist immediately.

• High-Pressure Compressor

It could be a compressor problem if the hissing sound has become a louder, more shrieking sound. Your outdoor AC unit may be experiencing high pressure should address this problem immediately.

5. Clicking sounds from your HVAC Unit

It is normal to hear a clicking sound during a cooling cycle. A clicking sound that doesn't stop is not normal. Let's take a look at possible causes.

• Obstructer in your AC Fans

The outdoor unit may be making clicking noises if it has an obstruction in its fans should be addressed immediately. You can perform routine maintenance or remove the cover from the outdoor unit and clean your fans.

• A capacitor loses its charge

The capacitor may lose its charge over time. The capacitor may lose its charge over time, and the compressor will not power itself. If this happens, you'll hear the compressor trying to turn off. For a complete checkup, you will need to call a professional.

• Fault in Electrical Signals

Faulty electrical signals can also cause switches to switch on and off repeatedly, making clicking sounds. If you notice sparks, turn off the unit immediately and call an HVAC technician. Sparks can be dangerous.

• Your AC Fan is Not Working

The clicking AC noise can be caused by an AC fan loosening and hitting the outside unit's case. The HVAC service will advise you whether the fan needs to be tightened or replaced.

• Thermostats that are not working properly

If your thermostat is not working properly, you'll hear a clicking sound, and the unit won't turn on. Normal thermostat operation will produce a soft clicking sound is because the relay switch sends power to the AC. If the relay fails to work or the wiring is damaged, it will send power but not turn on the unit. You cannot fix this issue; contact a professional to fix it.

6. The AC makes a whistling sound

Your air conditioner is making a loud, whistle-like sound? Although it may not sound as loud as other noises from your air conditioner, this noise signifies that something is wrong. These are possible causes:

• AC Duct Has a Leak

Your central AC's leaky duct can make noises similar to someone whistling. Sealing the ductwork is the best solution. Leaky ducts can cause noise and energy loss, which can lead to higher bills.

• Obstructive AC Air Flow

An obstruction blocking the airflow to your AC will result in high pitch whistling sounds due to the increased pressure on the blower motor. Dirty air filters block airflow and force the blower motor to pull air into the unit. Whistling sounds will be made by the air moving through cracks can prevent this problem by cleaning the filters often.

7. Air conditioner making a hum

Although an AC motor emitting soft humming sounds is not unusual, it can be alarming if it becomes louder. If your air conditioner is humming, it could be because:

• The Lubrication Level Is Too Low

Motors that need lubrication may emit a hum in the beginning. If you don't fix the problem, it will make a grinding sound. If you are familiar with lubricating motors, it is possible but not recommended that you do so.

• Contactor Failure

The contractor controls your air conditioner's electricity flow the contractor acts as a bridge connecting your air conditioner to the power source the contactor opens when the air conditioner turns off disables the power supply the reverse happens when you turn it back on.

AC contactor failure can cause humming sounds is when the AC gets power but cannot turn it on. It is important to address the problem immediately as it can lead to a loud buzzing sound.

• Bent Fin Coils

If the fin coils are bent, you may hear humming sounds. To fix bent fins, you can use a metal comb. Regular HVAC maintenance will keep your fin coils in top shape.

8. AC Makes a Crackling Sound

If the temperature is too low or the moisture isn't draining properly, or the fins get dirty, your HVAC unit can cause the evaporator's coils to freeze. The crackling sound of ice falling from these coils can echo through your HVAC system.

You can troubleshoot the problem by disassembling your AC and accessing the fins. Use dish soap to clean the fins thoroughly. Dry them. If you've done it before, don't attempt to disassemble the AC.

9. Buzzing noise from an air conditioner

Do you hear loud buzzing sounds from your air conditioner? It could be a sign of a variety of problems.

• Compressor Malfunctioning

AC compressors that make a loud noise are likely to have failed. It may still be getting power even though it is no longer working is known as a buzzing sound. It is expensive to replace the compressor.

• Loose parts

You may feel vibrations when your HVAC system is running if there are any loose parts.

• Capacitor Failure

Bad capacitors can cause the fan to stop turning on or cause friction noises. The capacitor stores energy until it's needed and then releases it to power your AC. An AC technician can inspect the capacitor and tell you if it should be repaired or replaced.

• Faulty Motor

A faulty motor can also cause buzzing. A buzzing sound can also be caused by obstructions or copper lines rubbing against one another. It is important to keep the lines well-insulated and minimize metal-on-metal contact.

• Contactor Failure

The AC's contactor controls the flow of electricity to its compressor. It can stop power flowing if it fails to function properly or wears out. Your HVAC unit will make loud buzzing sounds when it tries to start but is unable to due to a defective contactor.

The sound can start as a hum, but it can become a loud buzz if it isn't treated.

• Loose Wires

A steady buzzing AC sound is usually caused by loosening wires. There is a high possibility of an electric spark, turn off the AC immediately and get the wiring repaired.

• Freezing AC parts

The freezing of the parts can cause your indoor AC unit to buzz. The indoor unit can freeze for many reasons, including too low thermostat settings, low refrigerant levels, and so on.

An HVAC technician can help you determine which problem you are experiencing.

10. AC Units Make Grinding Noise

An issue with your compressor or motor could cause a grinding sound from your AC.

• Compressor Failure

A compressor problem is indicated by a grinding sound coming from the outside unit a defective compressor can make a loud grinding sound while it is operating

it is usually better to replace the compressor as a whole than to repair its internal components.

• Motor Failure

Your HVAC motor may be causing grinding sounds from your unit. Can prevent this noise by oiling your motor in the winter and summer seasons.

11. Bubbling & Gurgling AC Noise

It is easy to confuse gurgling and bubbling sounds, which could be the same problem. Here are some reasons they might be happening:

• Proper sealing of refrigerant lines

These sounds are usually a sign of a refrigerant problem. A gurgling sound can be caused by air trapped in refrigerant lines. Refrigerant leaks can cause a bubbling sound and a hissing sound.

• Sealing the lines properly is the solution.

• Excessive moisture in your AC

Excess moisture in an AC can cause bubbling sounds. A blockage of the condensate drain can cause moisture buildup. This line removes moisture from your home that AC has collected. It makes a bubbling or gurgling sound because water cannot escape the line.

The same problem can occur if the condensate pumps are damaged. Its purpose is to move water from your drain pan to the condensate lines. The pump may make bubbling sounds if there is too much moisture.

To inspect the drain line, you can take apart your air conditioner. It is not recommended to replace the drain line by yourself. For inspections and repairs, contact a certified technician.

12. AC Makes a dripping sound

A noisy AC that sounds like it is dripping could be a sign of trouble. Don't panic if you hear the AC making a noise that sounds like it is dripping could be caused by excess moisture in the drip pan is perfectly normal is normal, but it can be a concern if the sound you hear is excessive condensation.

• High Condensation

The drip pan can overflow if there is a lot of condensation can be removed by emptying the drip pan.

• Freezing AC Coils

You will hear a dripping sound as the ice melts from the coil it would help if you inspected the coils for any malfunctioning thermostats or dirty air filters.