Why Is My AC Making A Buzzing Noise?

August 16, 2023

Hearing a buzzing sound from your AC unit can be concerning, as it might indicate an underlying problem that could leave your home uncomfortably warm. Addressing this noise promptly is essential to keep your cool and avoid potential hazards. HVAC systems with issues have been linked to residential fires, with mechanical malfunctions accounting for 86% of AC-related fires.

Identifying the source of the buzzing is crucial to restore tranquility to your home and maintain your safety. Some common culprits include:

Electrical issues
Frozen evaporator coils
Broken or malfunctioning fan motor
Loose or damaged components

Although these issues can be disruptive, there's no need to fret. Our experienced team is ready to diagnose and resolve the problem, efficiently getting your AC back up and running. Ensure your comfort and peace of mind - Let us handle the buzzing noise so you can enjoy a refreshingly cool home again.

Ready to figure out why your AC is buzzing? It’s time to call a professional.

Advanced Air offers fast and convenient scheduling to help you get your AC working properly again as soon as possible. With thousands of 5-star reviews, you can trust that we have your best interests in mind. Call us today at (888) 853-5143 to schedule your appointment in Naples, Fort Myers, or one of our other service areas.

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An Electrical Issue

Buzzing coming from an air conditioner could be caused by an electrical issue within the unit. Unfortunately, electrical issues can do more than just leave you with an AC unit that doesn’t work. They could also result in hazards like electrical arcs and the potential for house fires.

Some common electrical concerns you might come across include:

A damaged or shorted circuit breaker: A damaged or shorted circuit breaker won’t work typically. Its job is to control the current going to the AC, but if the breaker is bad, too much (or too little) current could be getting to your AC.
A malfunctioning contactor: A contactor is controlled by your indoor thermostat. As the contactor goes bad, it could start humming or buzzing before eventually dying completely.
A bad capacitor: AC units have a capacitor that stores energy and then releases it when the fan motor needs power. The capacitor acts like a battery, ensuring the system turns on when you press the power button. If it goes bad, the unit might struggle to turn on, which could lead to buzzing.
Arcing: Electrical arcing is dangerous — arching produces an obvious electrical current that jumps between circuits and can electrocute anyone who gets too close. Additionally, it can short out parts or cause a fire.
Damaged wiring: Damaged wiring can lead to buzzing as the unit overheats or struggles to work with less power than it needs. Frayed, chewed, or disconnected wires are also a fire hazard.

Electrical issues tend to result from wear and tear, but they can also be from animals getting into the unit and other issues. Our team can help diagnose electrical issues and repair the problem.

Frozen Evaporator Coils

Frozen evaporator coils could be to blame if your outside AC unit is making a loud buzzing noise. Evaporator coils absorb the heat from the air in your house, so if they’re not working well, your house may be warmer than you’d like.

You can usually see if frozen evaporators cause your AC issues if you look at your AC unit outside. You may find:

Ice around the refrigerant line
Condensation and moisture around the air handler
A full or overflowing drain pan
Water leaks

Low refrigerant levels, dirty air filters, closed vents, blocked vents, and other problems can cause frozen evaporator coils.

If you suspect a frozen evaporator coil, turn off your system at the breaker box and wait for a professional to inspect your unit. Turning off your system will help prevent further damage.

Fan Motor Is Broken or Malfunctioning

An AC making buzzing noise could have a malfunctioning or broken fan motor. A fan motor pumps the air through the system. Without it, your AC will stop cooling the air and leave your home sweltering inside.

Signs of a broken fan include:

A fan that won’t turn on
A fan that won’t stop spilling
An intermittent fan

In any case, having one of our professional HVAC technicians take a look and see what’s going on is a good idea.

Loose or Damaged Pieces and Parts

Finally, one of the more common reasons for ACs to stop working is because of broken, loose, or damaged pieces and parts. Listen to your AC carefully. Do you hear any rattling or banging? Is there a clattering sound?

If so, there could be loose pieces inside. Broken parts of the fan, rocks, and other kinds of debris could cause the sound. On the other hand, if you don’t hear rattling but do hear a buzzing with some clicking or tapping, your fan could be damaged. Each rotation may be hitting the fan housing and causing an unusual sound. If you have an AC unit making a buzzing noise, it's time to have one of our HVAC pros diagnose and solve the issue.

Need to chat with a reliable, helpful HVAC technician today? We're here for you.

At Advanced Air, we’ve been working with local homeowners since 1989. We offer fast scheduling and no-surprise pricing, helping you get your AC system repaired and running within 24 hours. Ready to chat with one of our honest, professional technicians? Give us a call today at (888) 853-5143, and we’ll help you get your AC working like new again.