Do you hear your air conditioner making a humming noise? An air conditioner making noise is usually not a concern, unless the sound varies greatly from its typical sounds. Don’t worry, if the AC is making a humming noise you’re not alone. In fact, this is one of the most common noises central air conditioners make. Sometimes the hum is louder at different times and sometimes the hum noise level is more intense with different AC brands.

A humming noise usually indicates the steady drive of the outside fan blade and motor, but a humming or buzzing noise could also indicate a mechanical or electrical issue. 

Common Causes of Outside Air Conditioner Noise

The heavy equipment making up a central air conditioner can be expected to make occasional hisses, pops, rattles and the like. When you hear persistent humming and buzzing, though, you may have a problem that calls for professional air conditioner repair. 

Hear a hum? Consider these Causes

Howard Air - A/C Making Humming Noise: Condenser Fan Turning
Condenser fan motor: The air conditioner’s fan motor could be seized (unable to spin) but power is still going to it, creating resistance that produces a loud and noticeable hum.

Howard Air - A/C Making Humming Noise: Relay Switch
Contactor relay switch: Inside your outside unit, the air conditioner contactor serves to turn on the outside unit when the house temperature rises to the level where cooling is required. This contactor can fail mechanically or electrically, and will produce an electrical humming sound at failure.

Why Does My AC Make a Humming Noise?

Howard Air - A/C Making Humming Noise: Faulty Wiring
Loose wiring: When electrical wires separate by just a little, an electrical arc can be created, which can produce a buzzing sound and the potential for an electrical fire.

Howard Air - A/C Making Humming Noise: Circuit Breaker
Circuit breakers: An overloaded circuit breaker can buzz if it is faulty and unable to trip, or your breaker panel can buzz from normal electrical flow. Get a qualified HVAC contractor to check it.

Howard Air - A/C Making Humming Noise: Condenser Fan
Condenser fan motor: Yes, it could hum (see above), but it can also buzz from resistance from the failed motor. Without the fan motor turning the fan, your home will not cool down efficiently.

Experts Only

For air conditioner repair, Phoenix, AZ, homeowners are wise to call professional HVAC contractors to diagnose and repair humming or buzzing noises. Electricity is dangerous; the circulating refrigerant in your home’s AC is also strong stuff that requires expertise. 

Contact Howard Air to Stop A/C Noise Today!

Most homeowners lack the proper training to diagnose or repair a central air conditioner, and considering the investment you placed in it, you cannot afford to risk further damage. We encourage you to contact Howard Air at (623) 201-5153, rather than attempt a repair yourself, if you hear buzzing or humming sounds coming from your air conditioner.