Why Is My Air Conditioner Making Noise?

image of man experiencing loud air conditioner noises

Air conditioners aren’t a hundred percent quiet. New units will also generate some sounds which are normal for their regular use. Noises are frequently due to normal operations, so there is no need to fret over them. However, an air conditioner making noise can also indicate a bigger AC problem that should be checked by a professional HVAC technician immediately. Noises typically point to a part (or several parts) that are not working as intended. As a result, the air conditioning system might not be running as it should.

Explore Our Air Conditioner Services Call To Schedule A Free, In-Home Estimate: (860) 399-6218

What Air Conditioner Noises Should I Watch Out For?

Modern air conditioning systems offer quieter operation than older ones. HVAC technology has made a lot of progress in that many models are now equipped with noise-dampening technology with variable-speed compressors. This way, the air conditioners produce noise at just 55 dB or less, which is the noise level an average dishwasher generates. A faulty air conditioner is likely to produce any of the following sounds:

Air Conditioner Is Buzzing

An electrical problem can be the reason behind your buzzing air conditioner. It might also be because the outdoor unit’s fan blade has become loose or unbalanced. Other reasons for the buzzing air conditioner noises can be a damaged outdoor fan motor, other loose parts, or dirty condenser coils. An air conditioner leaking refrigerant also usually produces a distinct buzzing sound.

Call Today: (860) 399-6218

Humming Air Conditioning System

multimeter and run capacitors of an outdoor air conditioning unit

A humming sound from your air conditioner can be pointing to a defective contactor relay switch. The air conditioner unit might not turn on when this component gets damaged. This is because the thermostat will send a signal to this switch to start the condenser. This issue is an electrical one and should only be handled by a licensed HVAC professional. Another reason for the humming noise is problems with the fan motor.

Clicking Air Conditioner

Clicking sounds can be confusing because it sounds similar to the noise the air conditioner makes during the beginning and end of the cooling cycle. However, continuous and frequent clicking sounds can be because of a thermostat problem. If this is the case, the thermostat might need to be replaced by a licensed cooling technician.

Air Conditioning Screeching Sound

air conditioner condenser fan close up

A distinct noise that a malfunctioning air conditioning makes is a screech. The most likely reason behind this problem is a malfunctioning fan motor of the condenser. This fan’s primary function is to remove the heat from the refrigerant. A damaged fan will lead to the air conditioner failing to lower indoor temperatures.

Damaged fan motors can also cause screeching noises. Blower fans help eliminate indoor heat and humidity, forcing the air to the return ducts to be cooled by the air conditioning system. The blower fan will distribute the cooled air throughout the house using the air vents.

Other likely reasons the unit is screeching are a faulty fan belt and damaged fan motor bearings. Call your HVAC technician right away when you have a screeching or squealing air conditioner.

Explore Our Air Conditioner Repairs Services Call To Schedule A Free Consultation

AC Unit Clanking

An air conditioner system that is clanking likely has a loose metal part hitting another metal component. This part needs to be replaced. If the outdoor fan or indoor blower has loose or unbalanced blades, they will hit other parts and cause a clanking sound. Ensure that you call an HVAC technician immediately when you hear this noise. Don’t let the problem escalate as your air conditioner only incurs more damage when a metal component hits another metal part. As a result, you’ll need costly repairs.

Air Conditioner Whistling

image of air conditioner refrigerant

A high-pitched or whistling noise that sounds like screaming is another symptom to listen to. An air conditioner producing this noise likely has a refrigerant leak or a compressor that has a high pressure within. Both of these are severe problems that should be left in the hands of a professional. Turn off your air conditioner immediately and call your local HVAC contractor when you hear this noise.

Rattling Air Conditioner

There could be loose debris, such as twigs, dirt, and leaves, in the outdoor condenser. These could be what’s causing a rattling sound within the air conditioning unit. This is easy to fix as you only need to open the condenser to remove the debris. If the outdoor unit is clean, the noise could be a problem with the air conditioner’s electrical contactor. Prevent the problem from getting worse by getting it fixed right away.

Call Us Today For A Consultation: (860) 399-6218

Cooling System Is Making A Banging Sound

A defective compressor can result in banging noises. Older air conditioners typically produce banging noises. After all, age and regular wear can result in the unit’s components becoming unfastened and loose. It could also be that an air conditioner component is broken. The likely broken parts are inside the compressor, and these are the connecting rod, crankshaft, or piston pin.

An imbalanced indoor blower can also cause banging. Your air conditioner likely requires a compressor replacement if this is the problem.

Schedule An Air Conditioner Repair Consultation

An air conditioner that sounds as if there is a drone or helicopter inside it might have a mechanical issue. Some of these issues are a faulty fan belt, malfunctioning fan, or a damaged blower fan motor. You will hear a whirring noise if there is a loose fan blade. The best-case scenario to have is there is trapped debris within the indoor blower fan or outdoor fan unit. If you know what it sounds like when a piece of paper hits a fan, consider it a warning when you hear it in your air conditioner.

Get Started - Call Us Today Read Our Reviews



An air conditioner that has undergone a proper air conditioner installation and has passed the manufacturer’s quality test should have a good 15 years or more under its belt, as long as they receive regular filter changes, HVAC maintenance, and are reasonably used. However, the unit will eventually age, and it might not work as it used to. Never assume that your air conditioner’s problem is a simple one if you are unsure what course of action to take. Call your local, trusted HVAC contractor so they can determine the problem and apply the correct solutions.

Call Wilcox Energy For All Of Your HVAC Requirements

When you need superior HVAC services on the southern Connecticut shoreline, call Wilcox Energy. We have the best professionally certified technicians for when you require outstanding heating and cooling maintenance, installations, repairs, and replacements. All our friendly techs have the skills, knowledge, and experience to ensure you always receive correct HVAC services.

Our company has the most affordable HVAC service prices in the area. Our tune-up services can increase your energy efficiency, comfort, and indoor air quality while reducing your home’s energy bills. We can recommend the most suitable HVAC repair or replacement solution for your needs and budget. Rest assured, all our work comes with a guarantee. Book a service appointment with Wilcox Energy today and get a free, in-home estimate.

Call Now: (860) 399-6218 Explore Our Case Studies

For more information about heating and cooling systems, be sure to contact Wilcox Energy. You can contact us at (860) 399-6218. We offer a full line of heater and air conditioner repairs, maintenance services, and installations.