Air Conditioning, Featured

Name That Tune: What a Humming Air Conditioner Means

Name That Tune: What a Humming Air Conditioner Means

All air conditioners make noise as they run, mainly from the blower fans and the compressors. When the dominant sound is a humming air conditioner, odds are, something isn’t working as it should. The most common problems associated with the humming sound include:

Indoor Noises

  • When you hear humming sounds from the air handler, it may be caused by a frozen motor. Some blower motors require periodic lubrication to keep their bearings turning smoothly. A lack of oil will seize the bearings and prevent the motor’s shaft from turning. It could conceivably run until it burns out.

  • Humming from the breaker box. Whenever you hear humming sounds near the circuit breaker panel, suspect a serious electrical problem and turn off the noisy breaker. If you can’t identify which, turn off the main breaker and contact a licensed electrician immediately.


A humming sound is much more likely to originate in the outdoor condenser and it could be coming from:

  • The compressor. This part does the heavy lifting in cooling systems and it could hum or buzz when it’s at the end of its lifetime. It could also indicate an electrical problem involving the compressor.Compressors sit on rubber isolation feet that can wear out or crack. Damaged feet can cause the compressor vibrations to amplify and cause humming sounds.

  • Frozen coil. It might seem counterintuitive, but a humming air conditioner may have a frozen coil. Coils freeze when the refrigerant level is too low or they’re too dirty. A frozen coil can do serious damage to a heat pump or A/C should the compressor continue to run.

  • Fan problems. The condenser uses a large fan to blow the heat off the hot refrigerant. There could be a problem with its motor or the fan blade, which could be loose or bent.

Whenever you hear a humming air conditioner and it’s not working as it should or the sound is isn’t part of its normal operation, contact the pros at Air Assurance to diagnose and fix it. We proudly provide HVAC services for Broken Arrow homeowners.

Our goal is to help educate our customers in the Tulsa and Broken Arrow, Oklahoma area about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, call us at 918-217-8273.