air conditioner noises

6 Problematic Air Conditioner Noises that Require Immediate Attention

The last thing you need to be dealing with during weather extremes is air conditioner noises.

Millions of Aussies rely on air conditioning to provide their necessary heating and cooling, so it makes a lot of sense that we all understand how an air con works and can also recognise signs of damage and faults.

Of all the potential issues, loud noises coming from an air conditioner are among the most obvious. Loud and unusual noises can be signs of a serious problem. And by being able to catch a fault early on, there’s every chance that you could save your AC unit before it gets beyond repair.

Here are six problematic air conditioner noises and what they represent.

compressor fan noise

1. Humming Sound

Most air conditioning units produce a low-level hum, and this can be completely normal. However, if the sound is louder than usual, there’s likely an issue with the fan motor.

The motor can produce loud noises when fan blades are partially blocked by dust, dirt or debris or if the motor itself is damaged. If the fan is blocked or the fan motor is producing a louder than usual noise, it’s advised that you call a professional for assistance.

Even unblocking the fan requires access to the compressor’s internal components, and interfering with these may affect your warranty.

air conditioner noises buzz

2. Buzzing Noise

It seems unlikely that a swarm of bees would set up shop within an AC unit, so an electrical fault is the more likely cause of buzzing noises. The buzzing sound could indicate an electrical discharge from damaged or loose wiring, which poses a significant safety risk and becomes a potential fire hazard.

Electrical faults must be dealt with immediately by isolating the power to the system if possible and then calling in aid of a heating, ventilation and air conditioning (HVAC) technician. Catching the problem early could save on potential repairs down the track.

air conditioner noises popping

3. Clicking or Popping

A single click or pop on start-up can signify that the air conditioner is communicating with the thermostat and is no reason for concern. If the clicking or popping noise remains consistent, then you may have a problem.

A defective relay or failing thermostat could be the culprit. Whatever the cause, it’s something that needs to be replaced, so check your warranty or call an air con technician for the appropriate fix.

If you rely on a ducted air conditioning unit, a popping or even banging noise can be caused by the differences in pressure between the air supply and return duct.

Another reason for noise can be the ducts expanding and contracting due to changes in temperature. Having a professional clean the system, seal any leaks, and adjust the duct dampers can help reduce the noise.

common squealing noise

4. Squealing Noise

A high-pitched squealing noise or squeak can be one of the louder noises produced by an air conditioner. The piercing sound can indicate that the blower motor’s belt has slipped and requires adjustment.

Most modern air conditioner systems no longer use a belt system, so this problem is exclusive to older systems.

And yet contemporary air conditioners can also produce a squealing noise if the bearings on the condenser have worn down from use or if the compressor fails. Both problems need to be addressed by a technician right away before they cause the motor to fail.

air conditioning noises rattle

5. Rattling Noise

Rattling noises are among the most common undesirable sounds to come from an air conditioner. It’s possible that debris has found its way into the system only to rattle and annoy.

A much more serious cause is that loose parts have broken off and are now rattling around in the ducts or fan.

If the outdoor compressor has experienced damage, then a fan blade may have bent and now brush the sides of the casing.

Whatever the cause, there’s potential for the damage to worsen, so call a professional ASAP who may be able to provide a simple solution before a big one or a replacement is required.

air conditioner noises hiss

6. Hissing Noise

If your noisy air conditioner produces a hiss, it could mean one of two things: that there’s an air leak somewhere in the system or that the compressor has sprung a refrigerant leak.

An air leak is a minor issue, one that’s more annoying than anything else.

A refrigerant leak, however, is a significant concern. Refrigerant gases are present in all split systems and ducted air conditioners. These gases treat the air passing through the system to provide the desired heating and cooling.

Leaking refrigerant gas will impede the performance of your air conditioning system, and as the gases contain hazardous chemicals, they can poison if inhaled and pollute if released into the atmosphere.

If you hear a hissing noise or your air con doesn’t heat and cool like it used to, then it’s time to call a HVAC technician to seal the leak and perform an air con regas.

Air Conditioner Noise Repairs

Noises can be a normal part of your air conditioner’s operation, but being able to tell the difference between the sounds of an operational motor and a damaged one could make all the difference to the lifespan of your system.

Lacking precognitive abilities, the best way to keep your air conditioner free from faults is with an annual air conditioner service.

A licensed HVAC technician can provide maintenance by duct cleaning, inspecting, and regassing a system so it can perform at its best during heavy seasonal use. A technician can also catch potential faults before they spiral into serious damage.

When you encounter one of these problematic noises, take it as a sign, and contact Metropolitan Air Conditioning 24/7 for emergency repairs and replacements.

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.

Published: 2021-05-04

Air Conditioning Specialists You Can Trust

Our Promise Going Further

Our specialists pride themselves with honest reliable services


Our fixed pricing structure guarantees transparency. You will always be quoted the complete costs before work can commence, and our expert technicians will guide you through the process.

Our specialists pride themselves with honest reliable services


Not all jobs are created equal, but all jobs are equally important. Whether it's a simple repair or ducted air conditioning install, we apply the same high levels of dedication and service no matter the scope of the work.

Professional Expert Technicians


Home is your castle. Your pride and joy. Our well-spoken technicians will show respect towards you and your property and always clean up after themselves.

Technician Zip Pay Payment Options Image
Technician Zip Pay Payment Options Image

Now Available!

Interest free Air Con with trusted pay later options

What Our Happy Customers Have to Say

Better service starts here

5 stars rating

I called them in the morning, and they were at my doorstep within a few hours. The technician was quick to identify the problem, had the necessary parts, and repaired my AC unit in no time.

Marion Minguillon - WA
5 stars rating

My AC was acting up, and I was worried about a hefty repair bill. However, the technicians quickly identified a minor issue, fixed it, and didn't overcharge me. I appreciate their honesty and expertise in troubleshooting the problem.

Sara Cribbs - VIC
5 stars rating

Thorough filter cleaning left no room for concerns, resulting in cleaner air and AC that requires less maintenance. Our home's air quality has improved dramatically, and we couldn't be happier with the outcome.

Lorenzo Rodriguez - SA
  • Mitsubishi Heavy Industries Air Conditioning Logo

    When looking for a leading supplier of wall mounted split systems, Mitsubishi Heavy Industries air conditioners offer reliable, high-quality heating and cooling perfect for Australian family homes.

  • Temperzone Air Conditioning Logo

    Temperzone is the award-winning global manufacturer of air conditioners and leaders in climate innovation with a wide range of systems suitable for Australian homes and commercial applications.

  • Bonaire Air Conditioning Logo

    Bonaire heating and cooling systems are economical, yet high performance. Their reliable air conditioners are manufactured in Adelaide and expertly designed to withstand year-round weather extremes.

  • ActronAir Air Conditioning Logo

    For incredible home comfort, you want ActronAir. Ducted systems or wall hung splits, ActronAir air conditioning has the best residential cooling solutions. You'll never complain about the heat again.

  • Fujitsu Air Conditioning Logo

    Stay comfortable all summer long thanks to Fujitsu air conditioning. Fujitsu ducted air conditioning units are perfect for Aussie homes so when you need repairs or servicing, call Metropolitan.

  • Sharp Air Air Conditioning Logo

    With over 100 years in the industry, Japan’s Sharp Air Conditioning is known for luxury products. Sharp air cons provide convenient and effective cooling performance, to deliver year round comfort.

  • Hitachi Air Conditioning Logo

    Are you ready to discover the incredible range of Hitachi air conditioners? We’re talking split systems, wall mounted, ducted heating and cooling and more. So plenty of options for achieving comfort.

  • Stadt Air Conditioning Logo

    STADT air conditioning is synonymous with high quality Australian owned ducted heating and cooling. For any STADT air conditioning service and repair, we are your Australian experts.

  • Haier Air Conditioning Logo

    With over 30 years in the industry, Haier is known internationally for its energy efficient and smart heating and cooling solutions. Haier heating and cooling is just a tap away.

  • Vulcan Air Conditioning Logo

    When you're after a Vulcan air conditioning service, you want Metropolitan. We're experts in Vulcan climate control, providing repairs and servicing for air conditioners.

  • Kelvinator Air Air Conditioning Logo

    Australians have enjoyed Kelvinator's cooling reliability for over 80 years. Whether you have a Kelvinator window air conditioner or Kelvinator split system, Metropolitan is here to help 24/7.

  • York Air Air Conditioning Logo

    For optimal year-round comfort from your AC unit, York is the name to know. Distributed by Bonaire, York air conditioners Australia offer superior AC solutions perfect for our Australian climate.

  • Lennox Air Conditioning Logo

    Lennox is a globally recognised brand with a great range of energy-efficient HVAC systems. Choose a Lennox air conditioner when craving that desirable climate control and year-round comfort.

  • LG Air Conditioning Logo

    LG is a world leader in consumer electronics, and its air conditioners are no different. From smart split systems to energy efficient ducted air conditioning, LG air conditioning does it all.

  • Midea Air Conditioning Logo

    Midea is an Australian giant with an international reputation for quality split system air conditioning. You can also find portable coolers and window boxes among the Midea air conditioner range.

  • Mitsubishi Electric Air Conditioning Logo

    Mitsubishi Electric supplies premium residential air conditioners in Australia. Their sophisticated designs, including their sleek wall split system models, are built to offer long-term comfort.

  • Panasonic Air Conditioning Logo

    The latest and greatest Panasonic air conditioners go beyond heating and cooling with air purifying features for healthier breathing. Sounds good, doesn’t it?

  • Rinnai Air Conditioning Logo

    Rinnai is a trusted household name in all things heating and cooling. From the Rinnai gas heater to inverter splits and reverse cycle ducted systems, there's a Rinnai solution for every Aussie house.

  • Samsung Air Conditioning Logo

    Samsung Air Conditioning is known for its reliability and performance. These efficient climate systems are as highly regarded as Samsung’s TVs, home appliances and popular Galaxy smartphones.

  • Brivis Air Conditioning Logo

    Brivis by Rinnai has been a titan in the air conditioning game for 50 years. With an impressive heating and cooling system range, the Brivis name goes hand in hand with quality and longevity.

  • Braemar Air Conditioning Logo

    Braemar has all your heating and cooling needs sorted. Evaporative cooling, ducted gas heating, space heaters, wall heaters, split systems and reverse cycle - Braemar has you covered year-round.

  • Carrier Air Conditioning Logo

    The Carrier air conditioning range is known for sustainability and affordable prices. As a leading Australian AC supplier, Carrier strives to improve the industry through innovative cooling solutions.

  • Breezair Air Conditioning Logo

    Are you after a market leader in evaporative cooling? You need Breezair. Breezair evaporative coolers are manufactured in Australia so you know you're getting cooling to stand the Aussie heat.

  • Kaden Air Conditioning Logo

    Simple solutions are the foundations of Kaden heating and cooling. Products like the Kaden split system are perfect for the ever changing Australian climate so you can always remain content at home.

  • Celair Air Conditioning Logo

    Celair is a leader in ducted evaporative air conditioning with over 40 years of experience behind them. Manufactured right here in Australia, Celair heating and cooling supports local Australians too.

  • NEC Air Air Conditioning Logo

    Beat the heat with a NEC split system. NEC has a heating and cooling solution that will keep you comfortable in all seasons. Experience superior energy efficient heating and cooling with NEC.

  • Coolair Air Conditioning Logo

    As an Australian owned and operated manufacturer, Coolair evaporative air conditioning makes a great high performance companion for anyone looking to escape the harsh heat of our great southern land.

  • Sanyo Air Conditioning Logo

    Sanyo air conditioning models were known for providing trusted AC performance. Although Sanyo no longer operates, Metropolitan can still offer expert 24/7 service to your existing Sanyo system.

  • Toshiba Air Conditioning Logo

    Toshiba air conditioning makes use of innovative DC Hybrid Inverter technology which automatically provides high capacity heating and cooling when necessary and minimises running costs when it’s not.

  • TECO Air Conditioning Logo

    TECO has been heating and cooling Australian homes for over 30 years. With split systems, multi splits, window/wall air conditioners and ducted air conditioning, TECO has the whole home covered.

Metropolitan Air Conditioning Service Reviews Metropolitan Air Conditioning Service Reviews