# Why do my lights dim when the air conditioner starts? 1. [Home](https://arlite.co/) 2. [Support](https://arlite.co/support/) 3. [Electrical](https://arlite.co/support/electrical/) 4. Why do my lights dim when the air conditioner starts? **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 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/) - [What should I ask before getting an air conditioner installed?](https://arlite.co/support/air-conditioning/questions-to-ask-before-air-conditioner-installation/) [Electrical](https://arlite.co/support/electrical/)[View all](https://arlite.co/support/electrical/) - [Why do my lights dim when the air conditioner starts?](https://arlite.co/support/electrical/lights-dim-when-aircon-starts/) - [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. Why does starting an air conditioner affect the lights? 2. What can make dimming worse? 3. Is it my home or the street? 4. What if I am planning a new air conditioner? 5. What to note for the electrician 6. Frequently asked questions Lights can dim briefly when an air conditioner starts because it draws a surge of power for a moment as its motor kicks in. A short, small dip that stays the same may not be a concern. Dimming that is getting worse, lasts longer, or comes with tripping, buzzing or heat should be checked by a licensed electrician. ## Why does starting an air conditioner affect the lights? Electric motors need more current to start than to keep running. When an air conditioner’s compressor starts, it briefly pulls a large amount of power, which can pull the voltage down for a moment. Lights on the same circuit, or sometimes the same part of the home’s wiring, show this as a brief dip. How noticeable it is depends on the size of the air conditioner, the wiring, the connections, and how many other things share the circuit. A small, brief dip at start-up can be normal, but the same effect gets worse if something is wrong behind the scenes. ## What can make dimming worse? In general terms, the causes electricians look at include: - the air conditioner sharing a circuit with lights or other appliances - wiring that is too light for the load it now carries - loose or deteriorating connections, which resist the flow of current and generate heat - a supply issue at the home’s connection to the street An air conditioner would normally be installed on a circuit of its own, so that it is not sharing with lights. If lights dim sharply, or the dimming has started recently or is changing, that may point to a fault, not a normal start-up effect. Dimming together with buzzing, heat, a burning smell or tripping If you see sparks or smoke, or smell burning, leave the building with everyone in it, including children and pets, and call 000. If dimming comes with buzzing, a warm or discoloured switch, fitting or power point, a circuit breaker or safety switch tripping, or a smell, stay away from that area, do not touch anything that looks affected, and call a licensed electrician urgently. These signs can point to a loose or overloaded connection. ## Is it my home or the street? If lights dim in neighbouring homes at the same moment, or flicker at times unrelated to your air conditioner, the cause may be on the network. Report that to your network provider’s faults line. If the dimming only happens inside your home and lines up with the air conditioner starting, that points to the home’s wiring and load. Diagnosing it involves testing the circuit and its connections, which is electrical work. In Queensland, electrical work must be done by a licensed electrician, and the Electrical Safety Office Queensland is the regulator. ## What if I am planning a new air conditioner? If you are adding or upgrading an air conditioner, ask the installer or a licensed electrician whether your switchboard and wiring suit the extra load. Older boards and circuits are sometimes not suited to large new loads, and an electrician can advise before problems show up. ## What to note for the electrician 1. When the dimming happens — Write down whether it only happens at start-up, or also while the air conditioner is running, and how long it lasts. 2. Which lights and rooms — Note which lights dim, and whether other things, such as the fridge or a television, are affected as well. 3. Other signs — Record any tripping, buzzing, visible scorch marks or smells. Do not touch anything to check. 4. The air conditioner details — Copy down the make, model and approximate age from the indoor unit label if you can see it, and when it was installed. ## Frequently asked questions - A brief, small dip can happen because the motor draws extra current at start-up. If it is getting worse, lasts longer or comes with other signs, have a licensed electrician look at it. - Repeated large voltage dips are not good for electronics and may signal a connection problem. A licensed electrician can find the cause. - Air conditioners are normally installed on a circuit of their own. A licensed electrician or your installer can tell you what suits your system. - If neighbours see the same thing, tell the network provider's faults line. If it only happens in your home, contact a licensed electrician. [Learn about Electrical](https://arlite.co/services/electrical/) ## Official guidance For the rules and safety information that apply to your home, go to the regulators and industry bodies directly. - [Electrical Safety Office Queensland](https://www.electricalsafety.qld.gov.au/) - [Energex](https://www.energex.com.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 - [ElectricalWhy are my lights flickering? Causes and when it’s dangerousFlickering lights can come from the bulb, a dimmer, a loose connection or a street fault; crackling or a burning smell is an emergency.](https://arlite.co/support/electrical/why-are-my-lights-flickering/) - [ElectricalDo I need a switchboard upgrade?Old fuses, frequent tripping, burn marks, no safety switches or new solar, EV or air conditioning loads are reasons to ask about an upgrade.](https://arlite.co/support/electrical/do-i-need-a-switchboard-upgrade/) - [ElectricalInstalling a home EV charger: what to ask an electricianA home EV charger needs its own circuit, spare space on the board and enough supply capacity, all assessed by a licensed electrician.](https://arlite.co/support/electrical/ev-charger-home-installation-electrical/) - [ElectricalWhy does my circuit breaker keep tripping?A breaker keeps tripping when a circuit is overloaded, shorted or leaking, or the breaker is worn; a licensed electrician should find which.](https://arlite.co/support/electrical/circuit-breaker-keeps-tripping/) ## 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. Why does starting an air conditioner affect the lights? 2. What can make dimming worse? 3. Is it my home or the street? 4. What if I am planning a new air conditioner? 5. What to note for the electrician 6. 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/electrical/lights-dim-when-aircon-starts/ Site index for agents: [llms.txt](https://arlite.co/llms.txt), [sitemap](https://arlite.co/wp-sitemap.xml), [developer resources](https://arlite.co/developers/).