Why a motor makes the lights blink
A motor needs far more current to get moving than to keep running. For a fraction of a second that surge pulls the voltage down slightly across your wiring and the line from the street, and lights, LEDs especially, show it as a blink.
Modern inverter air conditioners ramp up gently, so a noticeable dip every time one starts is worth mentioning when you book. An older fixed-speed unit, a pool pump or a fridge compressor that is struggling to start can cause a bigger dip than it used to, and that is a job for the appliance's technician.
When dimming points to a fault
Watch what happens after the start. Lights that dip and come straight back are usually fine. Lights that stay dim while the appliance runs, dim more each summer, or flicker whenever the house is busy suggest resistance somewhere in the supply path: a loose connection at the main switch, the neutral link, the meter box or where the line from the street meets the house. Joints like these heat up under load.
If some rooms go dimmer while others go brighter, or appliances hum and struggle, the supply's neutral may be damaged, and your electricity distributor needs to know straight away. Energy Safe Victoria lists flickering lights among the warning signs of faulty wiring.
Dips from load, not faults
Some homes have simply outgrown their supply. A consumer mains cable sized decades ago for lights, a fridge and a washing machine may now feed ducted air conditioning, an induction cooktop and an EV charger. When everything runs at once, the voltage sags further than it should.
From the point of supply onwards, the installation is the owner's to maintain. We measure the voltage under load at the board, check the connections from the meter box in, and tell you whether the fix is a repair, splitting a busy circuit or a switchboard capacity upgrade.
What you can safely do now
- Note which appliance starts the dip, how long it lasts and which lights are affected. A short phone video helps.
- If lights through the whole house are dull, flickering or brighter than usual, keep away from the switchboard and anything metal, switch off and unplug what is easy to reach, and let your electricity distributor know.
- If a tap or appliance gives you a tingle, stop using it and let your electricity distributor know.
- Turn off a light or switch that buzzes, feels warm or smells hot.
- If there is smoke, fire or immediate danger, get everyone out of the house.
Services that can help
Read more in our guides
Related questions
- Why do my lights flicker on windy days?If your lights flicker when the wind blows, the overhead line to your house is the first suspect.
- Why does the kettle or toaster trip the safety switch?Usually the appliance has a fault that lets a little current leak to earth.
- Why does my power point only work some of the time?A power point that comes and goes has a connection that is making and breaking contact.
- Why does my light switch buzz or feel warm?A dimmer can hum faintly and feel a little warm, because it is an electronic device that sheds some heat while it works.
Sources for this answer
2 sources, with the date each was checked
- 1.Energy Safe Victoria: Old switchboards, particularly those without a safety switch Old power switches or power points, particularly broken ones Flickering lights Sparks from switchboards, switches or power points. If your house is over 30… Accessed 30 September 2026.
- 2.Energy Safe Victoria: The point of supply is the changeover point from the electricity distribution network to the electrical installation, where the property owner becomes responsible for the maintenance and repair of the electrical… Accessed 30 September 2026.
General information for homes in Victoria. Every installation is different, so treat this as a starting point. Where this answer refers to Victorian safety or rental rules, the sources above have the current requirements.