8 Most Common Types of Aircon Noises

Is your window air conditioner making an unusual noise? Is it disturbing the silent ambience of your quiet room in the middle of the night?

With the development of sound-dampening technology, as well as the two-stage (variable speed) compressors to keep noise levels below 55 dBs, our air conditioners are now quieter than ever.

If you notice that your unit is making weird noises, it is likely that there is a singular internal issue or multiple faulty parts clashing together inside the unit. Of course, some sounds might mean nothing. However, it is better to know what the most common sounds are and what they mean for your air conditioner unit.

Read on to find out 8 most common types of aircon noises and help diagnose any potential issues with your system.

Rattling Noises

aircon installation
aircon installation

Well, the condenser is the outdoor portion of an air conditioner that either releases or collects heat. With the exposure to dirt or tiny particles, it can end up accumulating debris which causes the unit to produce a rattling sound. To solve this, you can simply disassemble the unit to remove these debris. Again, this is why 338 Aircon emphasizes on the importance of regular aircon cleaning. Read here for 5 Creative DIY ways to clean your air conditioners.

If you hear rattling noises despite cleaning your unit regularly, you are recommended to get your electrical contractor in your system checked. Otherwise, a malfunctioning contractor can cause damage to the compressor.

Banging Noises

Banging is typically an absolute indication for loose or broken parts inside the compressor. When the components become unfastened in the compressor, it will hit the compressor’s exterior framing, which explains the loud banging sound. As such, regular aircon servicing helps to detect such problems. Click here to find out the top 5 benefits of servicing your aircon unit regularly.

Screeching Sounds

The fan motor is a vital part that enables the air conditioner to do its job as it blows air in and out of the house. Malfunctioning fan motors in the outdoor condenser unit can cause an aircon to produce incessant screeching sounds.

Screeching sounds can also be caused by damaged bearings in your fan motor. Aside from that, you might want to inspect to see if the fan belt needs repair. Read this article for 5 aircon parts that require regular maintenance.

Humming Noises

The purpose of an air conditioner relay is to send electric power to the air conditioning compressor and air conditioning compressor clutch when the system receives a signal from your thermostat. When the aircon relay switch is defective due to electrical or mechanical damage, a humming sound can be heard.

Buzzing Sounds

A buzzing noise from your outdoor condenser unit could be a signal for loose parts, damaged blowers or even unbalanced fan blades. Do also check if there are any problems with the condenser coils as it may become clogged with dirt or dust over time.

In the worst-case scenario, it might be due to a refrigerant leak, resulting in your air conditioning freezing up. If your unit is running outside but not cooling inside, this could be why.

Clicking Sounds

It is normal for your air conditioner to make a clicking sound at the beginning or end of your cooling cycles. It usually means that the thermostat is communicating with your unit.

However, a continuous clicking sound from your air conditioner may imply that there is a problem with your unit. This type of clicking sound may be an indicator of an electric problem or a problem with the compressor.

In that case, please turn the air conditioning unit off and call the professionals to examine your system immediately. Here’s a guide to choose the suitable aircon servicing company that caters to your needs.

Hissing Noises

One reason you may hear a hissing or whistling sound coming from your air conditioner is that there is a refrigerant leak, resulting in an escape of gas. This poses a serious problem as the loss of refrigerant can lead to damage to the compressor, which can jeopardize your entire unit. Read this article for 8 incredible tips on how you can check if there is an aircon gas leak.

It can also be caused by an internal valve leak or malfunctioning compressor.

If you’re only hearing periodic hissing noises, it is most probably caused by the expansion of the internal valve, which is not a problem. Otherwise, you might want to contact the professional technicians immediately to find out what’s wrong and to fix the problem as soon as possible.


A gurgling or bubbling sound can be caused by excess moisture due to a blockage, crack or hole in your drainpipe.

The air conditioner drainpipe, otherwise known as the condensate drain, is used to drain the moisture your unit collects from the air outside of your home. However, if something is clogging the drainpipe, it will create a gurgling noise since the water will not be able to exit your home easily. To learn about other causes of the gurgling noise, click here to find out more.

If you are a handy individual with the tools and equipment required, you might want to consider turning off your system and inspecting the drain line on your own. Otherwise, please call a certified technician to ensure a proper job is done. If you’re choosing between calling a professional or servicing your own air conditioner, you might want to read this article.

Quality Aircon Servicing, Repair & Cleaning – Aircon 338

Wondering why your aircon is making weird noises, we’re here for you when you need us.

We offer professional repair and services for your air conditioning equipment. Aircon 338 is experienced in aircon services such as chemical wash, cleaning, gas top up and installation services in Singapore.

If you are looking for cheap aircon servicing Singapore, we are the cheapest aircon service Singapore. Head over to our website to read candid reviews from our customers.

Call us at +65 9222 4141 to find out about the different aircon servicing package. Do WhatsApp us to get our unbeatable aircon servicing packages at low prices!