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.

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.

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.

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.

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.

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.

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.