Why Is My Outside AC Unit Making a Loud Noise

Is your air conditioning unit keeping you up at night and annoying you throughout the day with loud noises? This probably means that it needs to be repaired. Depending on what kind of noise your unit is making, there are different causes and solutions for each sound. In the Waco summers, it’s no doubt that we are all worrying about the well-being of our air conditioner. Avoid further damage to your unit by contacting Evergreen Heating and Cooling as soon your AC starts making unwanted noises, aside from the usual starting and stopping of a cycle. 

Common Sounds an AC Unit Can Make

It is normal for your air conditioning unit to make a quiet sound when it kicks on and off but there are many loud noises that you should look out for to keep your unit in the best condition, including

  • Banging Noises
  • Screeching Sounds
  • Humming Noises
  • Rattling Noises
  • Clicking Sounds
  • Bubbling Sounds

So what do each of these noises mean for your AC unit and how can they be resolved? 

Banging Noises

If your unit is making banging noises, it is most likely due to a loose or broken part inside of the air conditioning compressor; this could be a crankshaft, connecting rod or piston pin. Banging could also mean that your cooling system is due for a compressor replacement or that your indoor blower is off balance. The best thing to do if banging noises are coming from your unit is to turn your system off and call an Evergreen technician. 

Screeching Sounds

If there are screeching or hissing sounds coming from your air conditioner, this is probably due to pressure built up in your compressor. High pressure in your system can be very dangerous, so if you’re experiencing this be sure to turn off your system and contact Evergreen Heating & Cooling as soon as possible to get a technician out to look at your AC unit. 

Humming Noises 

Usually, if your AC unit is humming, it is not as serious of a problem. Although, it does mean that something is off with your system. Humming or buzzing noises can be caused by electrical issues, loose parts, refrigerant piping, loose wiring, or if it won’t start, motor issues. If any of these things are not quickly fixed, it could lead to serious maintenance problems, so it is important to reach out to an AC repair technician as soon as possible. 

Rattling Noises

There could be many different reasons your AC unit is making rattling noises. There could be debris in your outdoor unit, a displaced fan blade, a damaged motor, or loose panels. If you have a displaced fan blade or damaged motor, you need to contact one of our professionals at Evergreen to come to fix your unit. If you have loose panels, make sure to tighten any loose screws, and, if the noise continues, make sure to contact a technician. If you have debris, have a professional come out to carefully clean your outdoor unit and make sure there is no damage to it. To prevent any debris problems down the road, make sure to keep any bushes or shrubs trimmed at least 3 feet back from your AC unit. 

Clicking Sounds

If your AC unit is making a constant clicking sound, this is most likely because of a bent, broken, or blocked fan blade. This fortunately just takes a quick fix or blade replacement from an Evergreen technician. Although, make sure to not let your unit continue to run with a broken fan blade because this could lead to greater damage to your system.  

Bubbling Noises

If your outdoor air conditioner is making bubbling noises, the problem is coming from the refrigerant lines. The lines are most likely not properly sealed and air could be trapped in the liquid coolant lines. This is a small problem and you can continue to run your AC with the bubbling noise, but make sure to contact a professional to figure out the root cause of the sound and get it taken care of. 

Contact Evergreen Heating & Cooling Today!

If you are faced with any of these loud and annoying noises coming from your outdoor air conditioning unit, be sure to contact us at Evergreen Heating & Cooling to take care of all your air conditioner repairs. 

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401 S 13th St,
Waco, TX 76706





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