Outdoor AC Unit Making Loud Noises? Here’s What They Mean

Sudden strange noises from your AC unit can create panic. Instead, it is better to know what these noises mean and what sounds indicate what the issue is. Once you know what the sound means, you can call Lancaster HVAC contractor for help and even help the technician by providing details to the problem you are facing.

Loud Noises Your Outdoor Air Conditioning Unit Can Make

  • Banging

Banging is similar to slamming. If this sound comes from your AC, it is a clear signal of electrical and mechanical malfunction.

Loose wiring, broken parts, internal springs, faulty switch, broken motors, or circuit breakers can cause noise. Try to find which component is loose and make the noise to get a timely repair or AC replacement in Lancaster.

  • Screeching

Screeching is the sound of metal rubbing against metal harshly. It could be produced by a failing motor in your condenser unit. If the fan is in your condenser, it will make loud screeching and squealing noises.

Similarly, if the motor inside your compressor is failing, it will create loud screeching sounds telling you to get help from professionals.

  • Buzzing

Constant buzzing is a sign of electrical malfunction. Loose connections, broken switches, faulty motors, broken capacitors, and broken internal components can produce this sound while your AC is on.

If you hear buzzing while the AC is off, it is because of a malfunctioning electrical circuit. All the issues involving internal and electrical components should be given to a professional HVAC contractor to deal with. Doing it yourself would only be dangerous.

  • Hissing

The hissing noise is mainly produced by leaking refrigerant. The copper coils that carry refrigerant throughout your home are reliable, but an accidental leak can cause you to run out of coolant.

When a leak forms, the refrigerant escapes with pressure producing a hissing noise. Since the refrigerant is toxic, do not try to fix the issue yourself. Call a professional for AC repair, and if the problem persists, you must go for AC installation Rosamond.

  • Popping

Sounds like popcorn popping indicates serious issues with your compressor. It happens when the liquid refrigerant is sucked up by the compressor instead of the warm vapors in the outdoor unit.

If your AC shows these signs, contact Lancaster HVAC companies expert before damaging your compressor. Call a pro to get immediate inspection and repair before the situation gets out of hand.

  • Whistling

Airflow is affected if the pressure inside and outside your AC unit changes. A whistling sound is produced when the airflow inside the vents is restricted.

The warm air running over the evaporator coils is cooled down and passed to your house. With limited airflow, the passing air produces whistling sounds telling you to call a professional on time.


No matter what time you think about fixing these issues, a professional inspection and service would work wonders for your damaged AC unit.

Find the best AC and heat pump repair in Lancaster, CA, at Brock Heating and Air. Call 661-917-4791 to schedule an appointment. We have special financing and maintenance plans ready for customization; choose yours now.