Why Is My Split System Air Conditioner Noisy? Common Causes and Repair Tips

Dealing with a noisy air conditioner? Still searching for answers? We’re here to help. Although the underlying issue may differ from brand to brand, there are many common causes behind why this is occurring.

As one of Melbourne’s leading heating and cooling teams, we’ve seen it all. Throughout this article, we’ll outline some of the most common causes so that you can identify the source of your noise-related issues.

Why You Shouldn’t Ignore Loud Noises

As our lives become more and more fast-paced, it’s only natural to leave certain things to the side. For many, a noisy air conditioner can take a back seat to work, family, or other household commitments.

However, when it comes to this issue in particular, it’s always best to get it resolved sooner rather than later. Beyond the obvious inconvenience, loud noises could be indicative of larger issues within the split system unit.

A noisy air con is also likely to be working harder than it needs to be. This not only affects its output, but also leaves you feeling the pinch of higher utility bills. If this is currently affecting you, call us now for dependable split system air conditioner maintenance in Melbourne. 

What Different Noises Could Mean

If you’re running the split system and it’s suddenly producing loud noises, these can manifest as a variety of different sounds. Let’s cover the most common now:

1. Banging or Clanking: A loud banging or clanking noise often indicates a loose or broken part within the compressor or fan. This could be a displaced fan blade, a damaged compressor, or a loose bolt rattling around inside the unit. Ignoring this noise can lead to further damage and costly repairs. If you hear persistent banging, it’s best to shut off the system and call a technician.

2. Hissing or Whistling: A high-pitched hissing or whistling noise is typically a sign of a refrigerant leak. Refrigerant leaks not only affect cooling performance but can also be harmful to the environment and your health. This sound may also come from a faulty expansion valve or high internal pressure. If you notice this, turn off the unit and contact a professional for immediate inspection.

3. Buzzing or Humming: A continuous buzzing or humming noise is often linked to electrical issues. This could be due to loose wiring, a failing capacitor, or a malfunctioning contactor relay switch. While a slight hum is normal, an unusually loud or persistent buzzing suggests something is amiss and requires an electrician or HVAC specialist to diagnose the problem safely.

4. Clicking: Some clicking noises at startup or shutdown are normal, but if clicking becomes frequent or continuous, it could indicate a failing thermostat, a relay problem, or an obstruction in the fan blades. If the clicking doesn’t stop or gets louder, it’s worth having a professional inspect the system.

5. Squealing or Screeching: A sharp squealing or screeching noise usually points to an issue with the fan motor or belt. While most modern split systems use direct drive motors without belts, older models may still have belt-driven systems that wear out over time. A worn-out motor bearing could also cause this sound. A technician can assess whether lubrication or part replacement is needed.

6. Gurgling or Bubbling: A gurgling or bubbling noise often comes from trapped air in the refrigerant lines or a drainage issue in the condensate line. This can impact efficiency and lead to potential water leaks. Cleaning the drain line or checking for refrigerant leaks should resolve the issue.

7. Rattling or Vibrating: A rattling noise can result from loose screws, panels, or other components in the unit. Over time, vibrations from normal operation can cause screws and bolts to loosen, leading to persistent rattling. This is generally an easy fix—tightening the loose parts should eliminate the noise. However, if the rattling is coming from within the compressor, professional servicing is recommended.

Need to get your AC checked? We’re your go-to source for affordable split system air conditioner maintenance in Melbourne. Speak with our friendly team now on 03 9738 2000.

Why Split System Air Conditioners Become Noisy Over Time

Over time, even the best-maintained split systems can start producing noise. This can be due to natural wear and tear, dust accumulation, or minor issues that develop into larger mechanical problems. 

Regular use can loosen screws, cause motor bearings to degrade, and lead to refrigerant imbalances. Additionally, exposure to external elements like wind, rain, and debris can put extra strain on the system, making it noisier.

DIY Troubleshooting Steps Before Calling a Technician

Before calling a professional, there are a few troubleshooting steps you can take. Of course, always proceed with caution. If you don’t feel comfortable, speak with a licensed technician and allow them to assess the split system for you.

• Check for loose panels and screws: Over time, vibrations can loosen screws and panels, causing rattling or vibrating noises.
• Clean or replace air filters: A clogged filter can force the system to work harder, leading to unusual noises.
• Inspect the outdoor unit: Look for debris, dirt, or objects that may be obstructing the fan or condenser unit.
• Reset the system: Sometimes, turning the air conditioner off and back on can resolve minor electrical glitches.

If the noise persists after these checks, always reach out to a licensed professional. They have the knowledge, experience, and training required to handle a wide range of issues in a safe manner.

When to Repair vs. When to Replace Your Split System

If your split system has become excessively noisy, it may be time to consider whether repairs will suffice or if a replacement is necessary. Here are some factors to consider:

• Age of the unit: If your system is over 10-15 years old, repeated repairs may not be cost-effective.
• Energy efficiency: Older systems tend to be less efficient and noisier. A new, quieter model may save you money in the long run.
• Frequency of repairs: If your air conditioner has required multiple repairs in a short period, replacement may be the better option.

Other Signs Your Split System Needs Servicing 

Loud noises are just one of many issues indicating that a service is well overdue. Other signs to be aware of include: 

Error Codes or Warning Lights: Many modern split systems display error codes when something is wrong. Checking the manual or contacting a technician can help diagnose the issue.

Reduced Cooling or Heating Efficiency: If your unit isn’t cooling or heating as effectively as it once did, this could be due to clogged filters, low refrigerant levels, or a failing compressor.

Inconsistent Airflow: Weak or uneven airflow can indicate blocked ducts, a malfunctioning blower fan, or issues with the motor.

Unpleasant Odours: Musty, mouldy, or burning smells coming from your air conditioner could suggest mould buildup, electrical issues, or overheating components.

Increased Energy Bills: If you notice a spike in your electricity bills without any change in usage, your system may be overworking due to underlying inefficiencies.

Frequent Cycling: If the unit is turning on and off more frequently than usual, this could be a sign of thermostat issues, dirty coils, or an improperly sized system.

Water Leaks: Excess moisture or pooling water around the indoor unit suggests a blocked condensate drain or refrigerant leak, which requires immediate attention.

Turn to the Experts in Split System Air Conditioner Maintenance

Whether at home or work, there’s no need to settle for a noisy and disruptive air conditioning system. At Maroondah Air Services, we’ve been keeping Melbourne households comfortable for more than 25 years. Our qualified HVAC technicians offer affordable repairs and split system air conditioner maintenance across the city.

All staff are experienced and familiar with the major brands and models. In addition, we offer everything from multiple appliance discounts to 3-month warranty and $50 off if we don’t arrive on time.