My Air Conditioner Making A Cracking & Popping Sound

A cracking or popping noise usually has to do with humidity or icing in your air conditioning system—but not always. In this guide, we’ll review both the potentially harmless causes of cracking/popping noises, and the more serious causes. We’ll also discuss what you can do to fix them. In some cases, you will not need to call a professional to solve your problem.

Note: if your AC is popping constantly or experiencing performance issues as well, it’s best to shut it down and turn off power to the unit (via the circuit breaker) until a professional can look at it.

Rare or Occasional Popping Noises May Not Be a Big Deal

The first question we ask people hearing cracking or popping noises from their AC is: how often?

If you only hear this noise once in a while, usually shortly after the AC kicks on in the first place, it might be a simple matter of the duct expanding due to temperature. This is especially true if the noise sounds metallic and echoey, like someone tapping on a big piece of sheet metal.

Ducts are made of thin, flexible metal. Sometimes, when the system is off, warm air can make its way into the ducts, and the warmth causes them to expand slightly. Then when the cold air from the air conditioner suddenly passes through, the metal cools and contracts rapidly. The result is a short serious of creaking or cracking noises followed by one loud pop.

This kind of thermal expansion is generally harmless, and if the noises are rare, you may not need to worry much—especially if AC performance is still fine. However, you should tell your AC professional next time their visit for a biannual maintenance visit. They can check your unit to make sure there’s not a deeper problem.

If this happens all season long, it may also indicate that your ducts are leaking air or not properly configured. If that’s the case, having them fixed could not only stop the noise, but lower your energy bills.

Ongoing Cracking or Popping Noises Can Be Serious

Unfortunately, sometimes a cracking or popping noise signals a deeper issue—one that needs to be addressed immediately. If these noises seem to happen constantly, or throughout the time the air conditioner is running, there’s a good chance it’s one of these two issues:

  1. The unit is icing up. In many cases, cracking and popping noises involve ice forming inside the unit. This can happen if the temperature is set too low or if it’s not draining properly. AC units have a sensor so that they know when ice forms, and they turn off to thaw out. The sound of cracking and falling ice then echoes through your system.To check if this is the issue, try setting your thermostat to a warmer temperature. If the noises stop, you might be just fine. However, if they come back after a short time, it likely signals a problem with the unit itself and you may need a professional repair.

    On some units, you can also check yourself to see if it’s draining properly. Simply pull out the removable drain pan and check the drain. If the pan is full of water and the drain is clogged, clean it out so that it drains normally. This will prevent a backup of cold water that can freeze up the unit. Always check your owner’s manual for instructions and never open up the compressor unit yourself.

  2. Water in the unit. If water is getting inside the sensitive parts of your AC unit, it can cause serious performance issues and damage, as well as cracking or popping noises. This is the most likely cause if your noise started shortly after a heavy rainstorm.If you think this may be the problem, turn off the unit and shut off power to the unit before you take further steps.

    Once power is off, it may help to visually inspect the outdoor unit for signs of debris or anything that could be blocking it and preventing water from running out. Again, if there is a drain pan you can safely check, see if it’s draining properly. And clean off any debris from the outside of the unit—do not open the unit itself.

    Unfortunately, if water is in the unit, most likely it’s deep inside the more sensitive components which are normally protected from rain. You will need to call a professional to handle it.

Of course, there are other possibilities as well. Everything from a bent fan blade to low oil in the compressor could be causing the noise. It’s important to have unusual noises in your air conditioner checked right away, as they won’t go away on their own—and the problem usually gets worse. A small repair today is generally much less expensive than a major breakdown later.

Talk to an Air Conditioning Expert Today

If you’re getting strange noises from your air conditioner, the sooner you get it looked at the better. Ambient Edge can help you. We are a highly-rated, friendly and NATE-certified AC repair service with over 15 years of experience in Nevada and Arizona. Our professionals can diagnose the source of your problem and fix it for good—with a 100% guarantee.

We handle:

  • Compressor issues
  • Icing and water issues
  • Ductwork
  • Comprehensive AC repairs
  • Emergency 24/7 calls
  • Routine maintenance and troubleshooting

No one offers better service or better results than Ambient Edge. Let us show you what we can do for you. Flat-rate estimates and a 100% guarantee on every job. Call us at 702-723-4704 or fill out the form to your right and speak with an AC pro today.  

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