A well-maintained air conditioner should operate quietly and efficiently. However, an air conditioner can begin to experience problems, especially as it gets older. If you’ve noticed a bubbling sound coming from your AC unit, it could indicate an issue that needs to be addressed. Learning about the potential causes of this noise can help you determine the best solution for taking care of the issue before it gets worse and leads to a more costly repair. Here are some possible reasons why your air conditioner is making a bubbling noise.

Refrigerant Leak

Hearing a bubbling sound in your air conditioner can happen because of a refrigerant leak. Refrigerant is a crucial component in the cooling process, and a leak can lead to decreased performance and potential damage to your system. In addition to the bubbling sound, other signs of a refrigerant leak may include ice buildup on the evaporator coil, warm air coming from the vents, or a constantly running AC unit.

Troubleshooting Tips

If you suspect a refrigerant leak, you will need to turn off your air conditioner and contact a professional HVAC technician. Trying to fix a leak yourself can be dangerous and may cause further damage to your system. An HVAC technician will locate and repair the leak, recharge your system with the appropriate amount of refrigerant, and ensure your AC is operating efficiently.

Blocked Condensate Drain Line

A blocked condensate drain line can also cause a bubbling sound in your air conditioner. As your AC cools your home, it also removes moisture from the air, which is expelled through the condensate drain line. If this line becomes clogged, water can become trapped, resulting in a gurgling or bubbling noise. Here are tips if you are dealing with a blocked condensate drain line.

Identify and Unclog the Blockage

Other signs of a blocked condensate drain line include water pooling around your indoor unit or a musty odor coming from your vents. To clear a clogged drain line, you can try using a wet/dry vacuum to remove the obstruction or flush the line with a mixture of warm water and dish soap. If these methods don’t resolve the issue, call a professional for assistance.

Preventative Maintenance Tips for Blockages

One way to limit future clogs is to regularly clean your condensate drain line. Another way to avoid these issues is to install a condensate drain line float switch to shut off your AC if the line ever becomes blocked again.

Air Bubbles in the Refrigerant Line

Air bubbles in your refrigerant line can also cause a bubbling sound as the refrigerant circulates through the system. These bubbles can result from improper installation or low refrigerant levels. Other signs of air bubbles in the refrigerant line include decreased cooling performance and fluctuations in temperature.

If you suspect air bubbles in your refrigerant line, it’s important to contact a professional HVAC technician for an inspection and repair. A technician will check the refrigerant levels, remove any air bubbles, and ensure that your system is functioning properly.

Malfunctioning Expansion Valve

A malfunctioning expansion valve can also produce a bubbling sound in your air conditioner. The valve regulates the amount of refrigerant within the evaporator coil, and a problem with this component can lead to poor performance and strange noises. Signs of a faulty expansion valve include inconsistent cooling, a constantly running AC unit, or a bubbling or hissing noise.

If you suspect an issue with your expansion valve, it’s recommended to reach out to a professional HVAC technician for a proper diagnosis and repair. A technician will inspect your expansion valve and determine the best way to take care of this issue. If a replacement is necessary, they will install a new expansion valve and ensure that your system is operating correctly.

Debris in the Outdoor Unit

Debris can sometimes find its way into your outdoor AC unit, whether it’s twigs, leaves, or dirt. Any of this debris can cause a bubbling or gurgling sound as the fan operates. This debris can obstruct the airflow and decrease your system’s efficiency. You may even notice reduced airflow from your vents, longer cooling cycles, or increased energy bills.

The easiest way to check for debris is to turn off your air conditioner and carefully remove any visible obstructions from the outdoor unit. Be sure to inspect the area around the unit and clear away any vegetation or debris that could restrict airflow. You will need to keep the surrounding area clean and trim any plants or bushes that are too close to the unit to reduce the chance of debris entering your unit.

Water Leaking into the Indoor Unit

A water leak into your indoor unit can cause a bubbling sound as the water mixes with the refrigerant or encounters the system’s components. Over time, this issue can lead to damage to your AC unit and your home. Signs of a water leak in your indoor unit include a bubbling sound, water pooling around the unit, and decreased cooling performance.

If you suspect a leak, you will need to turn off your air conditioner and inspect the unit for any visible signs of water damage. You may need to call an HVAC technician to locate the leak and repair the issue. Regularly inspecting your AC unit and surrounding areas for signs of water leaks and addressing any issues promptly is essential to avoid damage to your system.

Faulty Compressor

A faulty compressor can produce a bubbling sound as it struggles to compress the refrigerant properly. The compressor is an essential component of your AC system, and a malfunction can lead to decreased performance and potential damage to other parts of the air conditioner. Other signs of a faulty compressor include warm air coming from the vents, frequent cycling on and off, and a tripped circuit breaker.

If you notice any issues with your compressor, you will need to contact a professional HVAC technician for an inspection. Attempting to fix a compressor issue on your own can be very dangerous and may void any warranties on your system. A technician will determine if your compressor can be repaired or if it needs to be replaced. They will also inspect the rest of your system to ensure that no additional damage has occurred.

Closing Thoughts

A bubbling sound coming from your air conditioner can be caused by several issues, ranging from minor to much more severe. It’s critical to identify the cause of the noise and address the problem promptly to prevent further damage to your system and maintain your home’s comfort.

Billfish Air Conditioning, LLC provides HVAC repairs and installation services for many customers in Stuart and the Treasure Coast area. Delivering quality HVAC for homes and businesses is always a priority. Our team is also available to answer any of your heating and cooling questions. Feel free to give Billfish Air Conditioning, LLC a call today if you ever need an inspection or repair service.

Meet the Author
Jason Culberson
Jason Culberson


Billfish Air Conditioning, LLC has been serving Stuart, FL & the Treasure Coast homeowners with top-rated HVAC services.
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