What do strange noises from my air conditioner mean?
The kind of noise points to the fault: whistling or humming usually indicates a fan or compressor problem, rattling means something has worked loose, and gurgling suggests refrigerant isn't flowing properly. A new noise that appears suddenly is worth checking sooner rather than later — a loose component left running eventually causes far more expensive damage.
How to recognise it
- Rattling or clattering from the indoor unit
- A high-pitched whistle on start-up
- Heavy vibration from the outdoor unit
- Gurgling or bubbling from the pipework
Common causes
Worn fan bearing
A worn bearing produces a rattle or whistle that grows over time. Replacing it early prevents damage to the motor itself.
Loose part or fastener
Years of vibration work screws loose. The rattling sounds alarming but the repair is usually straightforward.
Refrigerant at the wrong pressure
Gurgling from the pipework usually means low refrigerant or liquid returning to the compressor — which damages the compressor if left.
How we handle it
- 1Listening systematically to locate the source
- 2Checking bearings, fans and fixings
- 3Measuring gas pressures where gurgling is present
- 4A quote before any component is replaced
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