Why Is My Outside Air Conditioner Making A Loud Buzzing Noise?

Causes of an outside AC unit making a buzzing noise

A buzzing noise is usually a sign that there’s an electrical issue with the AC. It’s just a result of your AC wearing down over time.

The noise you’re hearing is usually a sign of “electrical arcing”, an electrical discharge you see when electricity is jumping between circuitry. Here’s a giant electrical arc to show you what we mean.

A few electrical components that could be causing the buzzing include:

• Contactor relay switch (a low-voltage switch in your outside unit controlled by the thermostat. It switches on high voltage to your outside unit’s compressor. It’s inexpensive to replace.)
• Circuit breakers
• Condenser fan motor (the fan we’re talking about is the big one in the outside unit. If the fan isn’t turning when the inside blower is working, the motor may be the source of the noise.)
• Electrical connections at any component

What you should do ASAP

1. Turn off your air conditioning system.
2. Call a professional air conditioning repair person and wait for help.

Even if your AC is cooling your house fine, that does not mean it’s OK to run. Running your air conditioner in this state could harm it (making the repair much more expensive than it needs to be.). So, it’s better to be safe than sorry.

For finding a good contractor, check out our article, Top 10 Essential Qualities to Look For in an HVAC Contractor.

Do you live in Florida? Cool Today may be able to help! We provide award-winning air conditioning service to homeowners in communities across Florida including Sarasota, Bradenton, Tampa, Orlando and Naples.

Posted in: Troubleshooting