5 Common Reasons Why HVAC Systems Produce Buzzing Noises

Like other home appliances and devices, a heating and air conditioning system can also experience hiccups after continuous use. However, the problems don’t come abruptly, as they will first manifest as random noises produced while the machine is on. But what are the common reasons why HVAC systems make buzzing noises? Here are some ideas.

1. Electrical Problems

Electrical problems are one of the most common reasons why HVAC systems produce buzzing noises. The electrical components of the system are susceptible to wear and tear. These components include circuit breakers, wires, and other electrical components.

If any of these components are damaged, it can cause the system to produce a buzzing noise. It’s essential to know that electrical problems can cause your system to overheat, leading to fires. Therefore, having it checked can prevent accidents from happening.

2. Loose Parts

HVAC systems are composed of many parts, some of which can come loose as time passes. When these parts are loose, it can cause the system to produce a buzzing noise. The most common loose parts are the fan blades, which can also cause the system to vibrate.

Another common cause of buzzing noises is the blower motor. The part allows the air inside the system. If it’s loose, it can cause the system to produce a buzzing noise. Although loose parts are not an urgent concern, they can worsen over time and cause machines to fail.

3.  Frozen Evaporator Coils

A frozen evaporator coil is one of the most common causes of buzzing noises. The evaporator coil is located inside the air conditioner and is responsible for absorbing heat from the air. The system will produce a buzzing noise if the evaporator coil is frozen.

A lack of refrigerant is the most common cause of a frozen evaporator coil. Refrigerant is a substance that helps to cool the air inside the system. If there is not enough refrigerant, the evaporator coil will not be able to absorb heat and will eventually freeze.

4. Damaged Isolation Feet

If your AC unit is mounted on the wall or ceiling, it will have isolation feet that help to reduce vibration. These feet can become damaged over time, which can cause the unit to produce a buzzing noise.

If you notice that your AC unit is making a buzzing noise, it is essential to check the isolation feet to see if they are damaged. If they are, you will need to replace them to stop the unit from making noise.

5. Clogged Vents

It’s essential to keep your AC unit’s vents clear of debris. The machine should stay clean to ensure its performance remains on top. If your vents are clogged, your AC unit will have to work harder to circulate air, which can cause it to produce a buzzing noise.

The best way to avoid clogged vents is by scheduling a regular cleaning session. Meanwhile, calling a professional cleaning company is an easier way to ensure cleanliness all the time. Choose the best cleaning company, Legacy Heating, for us to come by and clean your system.


If your AC unit is buzzing, there might be a problem. However, many factors can cause your AC unit to buzz. Some issues are easy to fix, while others are more complicated. But it’s best to ask Legacy Heating and Cooling for help. An AC technician can diagnose the problem and fix it right away.

Keeping HVAC systems maintained helps them last longer than expected. The longer they last, the better value for money homeowners get. Therefore, consult an expert and work with them to ensure HVAC systems have a longer lifespan today.

Legacy Heating is a furnace maintenance company in Calgary and Edmonton helping homeowners maintain and prolong the lifespan of their heating and air conditioning systems. We aim to ensure our clients get the value out of their HVAC systems by doing maintenance work on their machines. Book an appointment on our website today, or get a free quote by calling us on our hotline.

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