# Why is my air conditioner making a loud or strange noise? 1. [Home](https://arlite.co/) 2. [Support](https://arlite.co/support/) 3. [Air conditioning](https://arlite.co/support/air-conditioning/) 4. Why is my air conditioner making a loud or strange noise? **Browse support** [Support home](https://arlite.co/support/) [Solar](https://arlite.co/support/solar/)[View all](https://arlite.co/support/solar/) - [How does a solar power system work in a Brisbane home?](https://arlite.co/support/solar/how-does-a-solar-power-system-work-in-a-brisbane-home/) - [How do I turn off a solar inverter safely?](https://arlite.co/support/solar/turn-off-solar-inverter-safely/) - [Do solar panels work during a blackout?](https://arlite.co/support/solar/solar-during-power-outage/) - [Can I add a battery to my existing solar system?](https://arlite.co/support/solar/add-battery-to-existing-solar-system/) - [Hail or storm damage to solar panels: what to do](https://arlite.co/support/solar/hail-storm-damaged-solar-panels-what-to-do/) [Air conditioning](https://arlite.co/support/air-conditioning/)[View all](https://arlite.co/support/air-conditioning/) - [Why is my air conditioner making a loud or strange noise?](https://arlite.co/support/air-conditioning/air-conditioner-making-loud-strange-noise/) - [Why is my air conditioner not cooling or heating properly?](https://arlite.co/support/air-conditioning/air-conditioner-not-cooling-or-heating/) - [Why is my air conditioner leaking water inside?](https://arlite.co/support/air-conditioning/air-conditioner-leaking-water-inside/) - [Why does my air conditioner smell musty or like dirty socks?](https://arlite.co/support/air-conditioning/air-conditioner-smells-musty-dirty-socks/) - [Can solar panels run my air conditioner at night?](https://arlite.co/support/air-conditioning/can-solar-panels-run-my-air-conditioner/) [Electrical](https://arlite.co/support/electrical/)[View all](https://arlite.co/support/electrical/) - [Why does my circuit breaker keep tripping?](https://arlite.co/support/electrical/circuit-breaker-keeps-tripping/) - [Why does my safety switch keep tripping?](https://arlite.co/support/electrical/safety-switch-keeps-tripping/) - [Burning smell or hot power point: what to do right now](https://arlite.co/support/electrical/burning-smell-hot-power-point/) - [Why is there no hot water? 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By Aaron Midgley, Arlite Energy Last reviewed 30 October 2026 4 minute read **No DIY.** Electrical work must be done by a licensed electrician. Never open, repair, test or modify electrical equipment yourself, even if it looks simple. This guide explains what is happening; it is not a how-to. **On this page** 1. Which air conditioner noises are normal? 2. What do different noises suggest? 3. Why shouldn’t I keep running it? 4. Can I fix a noisy outdoor unit myself? 5. Could the noise come from the installation? 6. Does noise mean the unit needs replacing? 7. What to note before you call 8. What does a technician do? 9. Frequently asked questions A loud or strange noise from an air conditioner can mean a loose part, debris, a worn fan motor, a failing compressor or an electrical fault. Some sounds are normal, but grinding, squealing, loud buzzing or clanking are not. Stop using the unit, keep clear and have a licensed technician find the cause. ## Which air conditioner noises are normal? Some sounds are part of normal operation. These include a soft whoosh of air, gentle clicks as plastic parts warm and cool, a trickle of water as condensation drains, and a short pause or hissing when the unit changes mode or runs a defrost cycle in heating. Outdoor units also hum while the fan and compressor run. What matters is whether the sound is new, louder than before or different in character. ## What do different noises suggest? - **Rattling or vibrating:** loose panels or parts, debris near the fan, or an outdoor unit that has shifted on its mounting. - **Buzzing or humming that is louder than usual:** can point to an electrical problem or a part under strain. - **Squealing or screeching:** often a worn fan motor or bearing. - **Grinding or clanking:** a moving part that is damaged or hitting something. This can quickly lead to bigger damage. - **Hissing that continues or bubbling:** can sometimes relate to refrigerant, and needs a licensed technician. It is not possible to diagnose these by listening alone, which is why a technician needs to see the system. ## Why shouldn’t I keep running it? A noisy part is often a part that is failing. Continuing to run the unit can turn a small repair into a large one, and some noises come with heat or electrical faults that carry a fire risk. Stopping early is the safer and often cheaper choice. Stop using the unit and call if You hear grinding, screeching, loud buzzing or banging, or you notice a burning smell, smoke, sparks or tripping power. Leave the building and call 000 for fire, smoke or sparks. Otherwise stop using the unit, keep children and pets away from it, and contact an ARC-licensed air-conditioning technician or the manufacturer. ## Can I fix a noisy outdoor unit myself? No. Outdoor units sit on mounts or brackets, often at height or on a roof or wall, and have fans and live electrical parts inside. Refrigerant work also needs a licence. Leave any inspection or repair to a licensed technician. ## Could the noise come from the installation? Yes. Units that were not mounted securely, pipes that touch walls, or a unit placed too close to a wall or fence can create noise or vibration. A technician can assess the installation as well as the unit. ## Does noise mean the unit needs replacing? Not necessarily. Many noises come from a single worn or loose part. The technician can tell you whether repair makes sense or if the system is near the end of its life. ## What to note before you call 1. Describe the sound — Write down whether it is rattling, buzzing, squealing, grinding or clanking, and whether it comes from the indoor or outdoor unit. 2. Record when it happens — Note if it happens at start-up, constantly, or only in cooling or heating mode. A short phone video of the sound, taken from a safe distance, can help. 3. Photograph the labels — Take a photo of the make and model label and any display codes, without touching or opening anything. What you can safely check Listen from a safe distance and note what you hear, where it comes from and when. Photograph or film the unit without going near the outdoor unit if it is on a roof, bracket or hard-to-reach spot. Read the manual’s troubleshooting section. ### What does a technician do? A licensed technician will check the mounting, the fan and motor, the compressor and the electrical connections, and report what is worn or faulty. They will explain the repair options before work starts. ## Frequently asked questions - A worn fan, loose part, debris or a strained component can all increase noise. A change in sound is a good reason to have it checked. - Occasional soft clicking as plastic parts expand and contract is normal. Loud or repeated clicking is worth reporting. - Some hum is normal while it runs. Loud or harsh buzzing can point to an electrical problem or a part under strain. - Yes. Running with a failing part can cause further damage, which is why stopping early is advised. [Learn about Air Conditioning](https://arlite.co/services/air-conditioning/) Related services: [Ducted Air Conditioning](https://arlite.co/services/air-conditioning/ducted-air-conditioning/) ## Official guidance For the rules and safety information that apply to your home, go to the regulators and industry bodies directly. - [Australian Refrigeration Council](https://www.arctick.org/) - [Energy Rating (Australian Government)](https://www.energyrating.gov.au/) - [Electrical Safety Office Queensland](https://www.electricalsafety.qld.gov.au/) Was this helpful? Written by the team at Arlite Energy, a Brisbane business that designs and installs solar, air conditioning and electrical work for homes and businesses. We write these guides in plain English so you know what is happening in your home. ## Related articles - [Air conditioningWhy does my air conditioner keep tripping the breaker?An air conditioner that trips the breaker or safety switch has an overload or fault that a licensed electrician needs to find.](https://arlite.co/support/air-conditioning/air-conditioner-tripping-breaker-safety-switch/) - [Air conditioningWhat do air conditioner flashing lights and error codes mean?Flashing lights and error codes are the unit's way of reporting a fault, and the meaning depends on your model, so note the pattern and call.](https://arlite.co/support/air-conditioning/air-conditioner-flashing-lights-error-codes/) - [Air conditioningHow often does an air conditioner need servicing?Many manufacturers and installers advise servicing every one to two years, but follow your manual and warranty and use a licensed technician.](https://arlite.co/support/air-conditioning/how-often-air-conditioner-servicing/) - [Air conditioningWhy is there ice or frost on my air conditioner?Some frost on an outdoor unit in heating mode is normal, but ice on an indoor unit or on a unit in cooling mode points to a fault.](https://arlite.co/support/air-conditioning/ice-frost-on-air-conditioner/) ## Still stuck? Tell us what is going on and we can arrange a call-out. [Book a call-out](https://arlite.co/contact/) On this page 1. Which air conditioner noises are normal? 2. What do different noises suggest? 3. Why shouldn’t I keep running it? 4. Can I fix a noisy outdoor unit myself? 5. Could the noise come from the installation? 6. Does noise mean the unit needs replacing? 7. What to note before you call 8. What does a technician do? 9. Frequently asked questions --- **Arlite Energy**, Unit 1, 1468 Anzac Avenue, Kallangur QLD 4503. Phone [(07) 3062 9299](tel:+61730629299), email [info@arlite.co](mailto:info@arlite.co). Monday to Friday, 7am to 5pm. Page: https://arlite.co/support/air-conditioning/air-conditioner-making-loud-strange-noise/ Site index for agents: [llms.txt](https://arlite.co/llms.txt), [sitemap](https://arlite.co/wp-sitemap.xml), [developer resources](https://arlite.co/developers/).