Is Your Aircon Making Noise? 5 Sounds and What They Mean in Singapore Homes

Aircon technician using a sound meter to check noise levels of a wall-mounted unit

If your aircon is making strange sounds, don’t ignore it. These noises often point to something that needs fixing. Whether it’s a clicking, humming, or rattling sound, each one tells you something about what’s going on inside your system.

This guide breaks down 5 common aircon sounds, what causes them, and what to do next. If you’re in Singapore and hear any of these, it’s time to act.

1. Clicking Sound

A clicking noise when turning your aircon on or off is usually normal. But if it keeps clicking throughout the cycle, it could mean:

• A failing relay switch

• Loose electrical components

• A worn-out thermostat

Fix: A technician will check the electrical panel and replace any faulty parts. If you keep hearing clicks, stop using the unit and book a check.

2. Humming Sound

A low hum is common when the aircon is running. But a loud or buzzing hum could mean:

• Loose fan motor parts

• Contactor coil issues

• Faulty capacitor

Fix: Don’t try to fix electrical parts on your own. Contact a technician for a proper diagnosis and part replacement.

3. Rattling Sound

If your aircon sounds like it’s rattling or shaking, check for:

• Loose screws or bolts

• Debris inside the unit

• A misaligned fan blade

Fix: Tightening components or cleaning debris usually solves this. If the rattling sound continues, it could wear out your fan motor.

4. Gurgling or Bubbling Noise

This happens when there’s air trapped in the refrigerant line or if the drain pipe is blocked.

Fix: A technician may need to flush the drainage pipe or inspect for a refrigerant leak.

5. High-Pitched Whistling

Whistling could mean:

• A refrigerant leak

• High internal pressure

• Faulty valves or air filter blockage

Fix: This is serious. Turn off the aircon and get it inspected immediately.

Illustration of five common aircon sounds, clicking, humming, rattling, gurgling, and whistling

When to Call a Technician

If your aircon starts making a sound it didn’t before, don’t wait. Some sounds seem harmless at first but can turn into costly repairs. A good rule: If it sounds unusual, get it checked.

FAQ

Q1: Is it safe to run my aircon if it's making noise?

No. Noise is often a sign something is loose or damaged.

Q2: What causes a rattling sound in the aircon?

Loose screws, fan blades, or internal debris.

Q3: Can I fix a clicking or humming sound myself?

Not recommended. Most noise issues involve internal components or wiring.

Q4: Why does my aircon gurgle when I turn it off?

There may be water trapped in the drain line or air in the gas line.

Q5: Do noisy aircons use more electricity?

Yes, especially if airflow is blocked or parts are straining.

Hearing strange sounds from your aircon? Contact Sky Blue Aircon Engineering Pte Ltd for a inspection and fast fix.