Strange noises coming from your air conditioner are never good. You’re probably wondering if the noise means there’s a serious problem with your AC system.
Note: If you hear any strange noises coming from your AC, we recommend turning off your system and calling a professional immediately. Letting your AC run could seriously damage your system or harm your home.
Unfortunately, without inspecting your condenser (your outside unit), there’s no way of knowing exactly what’s wrong with it.
But to give you an idea of what could be the problem, we’ll go over the following noises and what they could mean for your AC:
We’ll also let you know whether or not you should turn off your AC for each noise.
Complaint: When your AC is running, you hear a loud, metal-on-metal screeching noise that won’t stop until the AC shuts off.
Probable cause: Your fan motor bearings are bad, which means you’ll have to replace the fan motor.
Complaint: Your outdoor unit makes a loud slamming noise when it shuts off or a banging noise while it’s running.
Complaint: You hear a high-pitched whistling or screaming sound for 10–15 minutes after the AC first kicks on. Your AC might also turn on and off frequently.
Probable cause: Your compressor has high refrigerant pressure. Some AC units have a sensor that shuts down the system if it detects dangerous levels of internal pressure, which explains why your AC might be turning on and off a lot.
Complaint: You hear a constant buzzing noise in your condenser, both when the unit’s running and when it’s not.
Probable cause: There’s an electrical problem in your system. The problem could be caused by the:
We’ll send one of our trusted AC techs to figure out what’s wrong with your AC and then repair it. In the meantime, turn your AC off to prevent further damage.
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