In a densely populated city like Singapore, a noisy aircon can disrupt your peace. It might even disturb your neighbors, as the sound could carry through to someone living right next door in your HDB flat.
Whether it’s rattling, banging, or chattering, these sounds often signal a problem within the compressor. But in some cases, it can also indicate a bigger problem within the unit that only an AC professional can fix.
In this article, we look at the possible reasons behind common AC compressor noises and what you can do to troubleshoot and fix the issue.
How Do Aircon Compressors Work?
An aircon compressor is the heart of your air conditioning system, responsible for circulating refrigerant and maintaining the cooling cycle. In Singapore, where air conditioners run almost daily due to the hot and humid climate, a well-functioning compressor is essential for indoor comfort.
Under normal conditions, an aircon compressor emits a low humming or buzzing sound when running. This is completely normal and indicates that the compressor is pressurizing the refrigerant to cool your space effectively. However, when the compressor becomes noisy, it may signal an underlying issue that needs immediate attention.
Causes of A Noisy AC Compressor
Reason #1: Loose Parts or Debris
Air conditioners have several parts that may come loose due to age or wear and tear. You can often hear a banging or rattling noise that indicates a part of your air conditioner has come loose and is rattling around your unit. Debris can cause similar sounds as the AC vents serve as entryways for large pieces of debris like stones, plastic parts, and screws.
Due to Singapore weather, the outdoor unit is most susceptible to harboring pieces of debris as it is exposed to the outdoor elements. Leaves, sticks, and nuts can find their way into the outdoor air conditioning unit, causing a rattling or banging noise when you turn the air conditioner on.
Reason #2: Faulty Fan Motor or Fan Blades
An air conditioner that emits helicopter-like sounds is most likely having issues with the condenser fan motor or blades. The motor may need to top up on lubricant, or the blades might have bent or misaligned, bumping into other components inside the unit.
The fan is located near the compressor, and the blades may be hitting the component, causing a grinding noise to come from your AC compressor. There may also be debris struck between the blades, or the fan may have come loose. These require immediate repair before the fan can further damage your unit.
Reason #3: Faulty Compressor
Sometimes, the noises coming from your air conditioner are actually coming from a faulty AC compressor. A grinding noise happens when your compressor is overworked or worn out, which is a common issue in older units or air conditioning units that are improperly maintained. The sound is caused by the worn-down piston pin forcefully working to compress the refrigerant.
A faulty compressor calls for an expensive compressor replacement, and depending on the gravity of the malfunction, professional HVAC technicians may recommend you to replace the entire unit instead of replacing or repairing the compressor.
Reason #4: Electrical Problem
A high-frequency humming or buzzing noise may indicate an electrical problem with your air conditioner. Your unit may have faulty wiring, exposed cables, grounded wires, or other issues with electrical parts. The buzzing or humming noise is caused by the electromagnetic field flowing currents of energy. This sound is usually quiet, so a loud noise indicates a problem.
Reason #5: Blockages or Pressure Inside Your Air Conditioner
A hissing noise would indicate a blockage in your air compressor, such as a clog, refrigerant leak, or debris blocking the valves. A squealing noise or screaming noise, on the other hand, is caused by high internal pressure from your air conditioner, which may indicate other underlying problems with your compressor.
These issues can cause further damage to your air conditioning system, so it is best to contact one of our experienced technicians to diagnose and solve the problem before your air conditioner breaks down.
Reason #6: Refrigerant Issue
If your aircon compressor hisses or bubbles, it could be due to a refrigerant leak. Refrigerant is essential for cooling, and a leak can cause the compressor to work harder, leading to overheating and inefficiencies.
In Singapore, where aircon units are used frequently, refrigerant leaks are a common issue among residential and commercial properties. If left unchecked, a refrigerant leak can not only make your aircon noisier but also reduce its cooling efficiency and increase electricity bills.
Reason #7: Leaking Oil
A screeching sound coming from the compressor may indicate low lubrication levels due to an oil leak. The compressor relies on oil to prevent metal components from wearing out. If oil levels drop, friction increases, leading to loud noises and potential compressor failure.
We’ve encountered this issue in many Singapore homes and offices, where aging or poorly maintained aircon units suffer from internal leaks.
Reason #8: Faulty Capacitor
If your aircon compressor is making a clicking or rattling noise, a faulty capacitor could be the culprit. The capacitor provides the necessary power boost to start and run the compressor. When it malfunctions, the compressor may struggle to turn on, causing clicking sounds as it attempts to start up.
Troubleshooting Guide
Tip #1: Check for Loose or Broken Parts
Air conditioner noises coming from loose or broken parts have relatively easy troubleshooting solutions. Flash a light through the vents of your air conditioner, and check for any debris that may be causing these noises. Unplug your air conditioner and remove the debris using a long stick, or open the housing to manually clean the inside of the unit.
Tip #2: Bend Misaligned Blades
Open the housing of the outdoor unit while your cooling system is unplugged, and look for the fan with misaligned blades. Bend the blades back into its original position, and do a test run of the fan to make sure the blades aren't hitting any other components.
Tip #3: Replace Faulty Parts
An air conditioner making noise from a bad AC compressor may be too late for repairs, but for other faulty parts such as malfunctioning motors or worn-out components, our Luce technicians will be more than glad to assist you in the replacement of these parts.
When it's time to replace your entire air conditioning unit, you can rest assured that our technicians will guide you through finding the right unit, brand, and model that fits your requirements. We'll handle the installation and checkup too!
Tip #4: Contact an Electrician for Electrical Problems
Any problems pertaining to electrical components must be dealt with by a professional. Refrain from troubleshooting the problem yourself, and instead look for a trusted and experienced electrician to fix the issue.
Tip #5: Schedule a Chemical Wash
An aircon chemical wash would keep your AC unit running properly and deep clean the dust and debris out of your unit. This is recommended to older units that have not been properly maintained in a long time, but you should consider a routine deep clean once a year as well.
All-Around Aircon Service Company
For aircon repair and maintenance, give us a call here at Luce! We are Singapore's trusted expert in air conditioning solutions, specializing in cleaning, repair, and regular maintenance services for all types of aircon units.
From general servicing to the full range of aircon repairs, our team of AC experts and technicians are here to help you solve your aircon woes in one appointment.
