Identify Sounds from Your Air Conditioner
- Normal Operating Sounds: These sounds may occur as the temperature changes or components operate.
They may include snapping, clicking, gurgling, hissing, or humming sounds. - Sounds That Require Inspection: These sounds may occur when components are touching, vibrating, or not working properly. They may include loud rattling, rapid tapping, or high-pitched sounds.
Find the description that most closely matches the sound you hear to check the possible cause and recommended action.
Note: The recordings were made while actual air conditioners were operating.
The volume may vary, parts of a sound may not be audible, and background noise may be present. Adjust the playback volume as needed.
Plastic Expansion
Snapping or Popping
You may hear a snapping or popping sound as internal plastic components react to temperature changes.
This is normal and similar to the sounds a TV makes as it heats up or cools down.
Wall-Mounted Air Conditioner Relay
Clicking, Clunking, or a Metallic Clicking Sound
Your wall-mounted air conditioner's indoor unit uses a power relay to supply power to the outdoor unit.
This relay may turn on every two hours to preheat the outdoor unit, making a normal clicking or clunking sound.
Drain Pump
Gurgling
Your ceiling-mounted air conditioner has an internal drain pump.
You may hear a gurgling or motor sound when the pump operates, especially in a quiet room. These are normal operating sounds.
Air Outlet Louvers
Thudding, Tapping, or Clicking
You may hear thudding, tapping, or clicking as the louvers move to adjust the airflow up, down, left, or right.
These sounds commonly occur when you first use the air conditioner or change the airflow direction.
The louvers make these sounds as they move through different angles and return to the correct position. This is normal.
If the sound is distracting while you sleep, check whether vertical or horizontal airflow is turned on. Turn off the airflow direction setting if you do not need it.
Bearing Operation
Soft Swishing
You may hear a soft swishing sound when the air conditioner operates at a low fan speed.
This normal operating sound may be easier to hear at night when the room is quiet.
Refrigerant Flow Inside the Indoor Unit
Hissing, Gurgling, or Trickling
You may hear hissing, gurgling, or trickling as refrigerant moves through the indoor unit.
These normal operating sounds may be easier to hear when the fan is running at a low speed or the room is quiet.
Concealed Drain Hose
Tapping or Water Dripping
You may hear a normal dripping sound from the indoor unit shortly after turning off your air conditioner.
This sound may occur where a concealed drain hose bends. To reduce this sound, extend the drain hose.
The dripping sound itself can be part of normal operation.
Exposed Drain Hose
Thudding
An exposed drain hose may hit the wall when it moves in the wind, creating a thudding sound This sound itself can be part of normal operation.
For a concealed drain hose, extending the hose may help reduce water dripping sounds.
For an exposed hose, secure the hose to the wall to prevent it from moving and reduce the noise.
Outdoor Unit Compressor Speed Changes
Humming
The compressor speed on your inverter air conditioner changes based on indoor and outdoor temperatures.
You may hear a humming sound that gets louder or quieter as the speed adjusts.
This can be a normal operating sound.
Indoor Unit Fan Contact
Loud Rattling or Rapid Tapping
A loud rattling or tapping sound may occur if the indoor unit fan touches the unit housing.
Contact LG Customer Support for service.
Outdoor Unit Compressor Vane Movement
Rapid Tapping
When the room temperature is close to the set temperature, the outdoor unit compressor may slow down.
A specific tapping sound may occur if the compressor frequency drops to approximately 10Hz.
If you hear a rapid tapping sound that stops when you select Power Cooling, it may be related to the compressor vane.
Contact LG Customer Support for service.
Outdoor Unit Fan Contact
Rapid Tapping
The outdoor unit fan may touch the front panel if the unit was impacted during installation or is not level.
Contact LG Customer Support for service.
Pipe Contact Inside the Outdoor Unit
Loud Rattling or Rapid Tapping
A pipe inside the outdoor unit may make noise if it touches the compressor or front panel.
Contact LG Customer Support for service.
High-Pitched Sound from the Outdoor Unit
High-Pitched Beeping or Whining
A faulty compressor, motor, or another internal component may produce a high-pitched sound. Contact LG Customer Support for service.
Outdoor Unit Mounting Bracket Contact
Loud Rattling or Rapid Tapping
The outdoor unit or its mounting bracket may make noise if the parts are touching or were not secured correctly during installation.
Contact LG Customer Support for service.
Warning
Do not disassemble your air conditioner or attempt to repair internal components.
Contact LG Customer Support to request service if you hear any of the following sounds:
Frequently Asked Questions (FAQ)
- Q. What Can I Do to Reduce Air Conditioner Noise?
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A. Dust buildup on the filter can restrict airflow and increase noise.
Wash the ultra-fine filter with water every two weeks to reduce noise and improve cooling performance.
Do not attempt to repair mechanical rattling sounds yourself. Contact LG Customer Support to request service.
- Q. Why Did the Outdoor Unit Suddenly Become Much Louder?
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A. High outdoor temperatures or objects blocking the unit can cause it to overwork and become louder.
Remove any objects around the outdoor unit to ensure proper ventilation.
This guide is based on standard models. The settings menu may vary by model.
