Hearing strange noises from your air conditioner is usually a sign something needs attention. Here are the most common sounds and what they mean.
Loud Rattling or Vibration Noise
Loose components in the outdoor unit, or debris caught in the fan. A simple fix — usually involves tightening bolts or removing debris. Cost: $80–$200.
High-Pitched Squeal or Hissing
This can indicate low refrigerant leaking. If you hear a hiss, turn the system off and call a technician. Continuing to run it with low refrigerant damages the compressor (expensive).
Grinding or Banging
The compressor is struggling. This is an emergency — stop running the system and call for same-day service. Compressor replacement costs $1,200–$3,000+.
Quiet Bubbling Inside the Indoor Unit
Usually refrigerant bubbling through the line — sign of low refrigerant or undersized system. Book a service inspection.
When to Act
If the noise is sudden and loud, turn the system off and call immediately. Call Jim on 0416 931 871 for same-day noise diagnosis across Sydney. 131 five-star reviews. ARC-certified. 25 years experience.