5 Common Reasons Your AC Makes a Buzzing Noise

Is your AC makes a Buzzing Noise? It’s normal for your air conditioning unit to produce a humming sound when turned on, which means that it is working properly and efficiently. When it is working well, it will provide you and your family with cold air, a cozy ambiance, and the utmost comfort. However, when it starts to produce a buzzing sound, you will notice that it doesn’t work as efficiently as before. This is common because there could be problems with your unit that might compromise its overall efficiency and performance.

In this article, we will explore five common reasons your heating and air conditioning unit produces a loud buzzing sound:

1. Frozen AC unit

After years of heavy usage, it is inevitable that your air conditioner freezes up. As a result, you’ll start to hear a buzzing noise brought by the frozen unit. When this happens, make sure to turn off your unit immediately and let it thaw for some time. After a few hours, turn it on, and it should be up and running. If the symptom persists, however, it is best to contact a professional at Legacy Heating & Cooling to get it fixed.

2. Condenser fan motor problem

The condenser fan serves to blow air from the outside unit when your AC is on. The problem occurs when its compressor motor emits a buzzing noise. This typically happens when the fan blades are not turning, but the inside blower is still working fine. The fan blades may not be turning because of loose parts, a malfunctioning fan, or debris inside. 

3. Isolation foot damage

Typically, your unit’s compressor is mounted on the base while it sits on a small rubber foot called an isolation foot. However, the rubber on the foot can get subjected to wear and tear over time. With a cracked or deteriorated material, the compressor may become unbalanced, which produces a buzzing sound. Be sure to contact an expert to replace the isolation foot and ensure a balanced compressor.

4. Compressor malfunction

The AC unit’s compressor serves to pressurize and cool the refrigerant. When you start to hear a buzzing sound, it means that the compressor is no longer functioning properly. Also, the electrical voltage may not be at the correct amperage. In that case, call a professional to see if the compressor is already malfunctioned and seek to replace it.

5. Loose AC parts

An air conditioning unit consists of various parts and components. As your unit works overtime, however, these components tend to vibrate so much that they become loose. This is why you’ll start hearing buzzing sounds produced by your unit. Know that even tiny parts can affect the overall performance and efficiency of your unit and your cooling experience at home.


Don’t ignore it if your AC makes a buzzing noise. A buzzing sound produced by your heating and air conditioning system shouldn’t be taken for granted. As outlined above, it can be caused by a frozen unit, a problem with the condenser fan motor, damage on the isolation foot, a compressor malfunction, and some loose parts. The best way to enjoy a smooth experience at home is to hire heating and air conditioning services to fix your AC unit to ensure its overall performance, efficiency, and longevity. If you’re thinking about using a Heat Pump to cool your home, we can help you with that as well!

We provide heating and air conditioning services in Calgary and Edmonton. If you need to get your air conditioning unit repaired due to a recurring buzzing sound, get in touch with us today to see how we can help!

HVAC Brands We're Proud to Carry

Legacy only uses the most efficient and cost-effective HVAC products. We pride ourselves on putting quality and customers first! We will equip your new home with the best HVAC system and offer the most reliable residential heating service in Edmonton and Calgary.

Contact Us Today

We’ll help you find the right heating and air conditioning system for you and your budget.

Edmonton Area 780-733-1256 Calgary Area 403-451-1337

Honesty, Integrity, Legacy