Electrical faults and solutions

Why do my lights flicker?

In short

One flickering light is usually the globe, a loose globe, or an LED that does not suit the dimmer or transformer it is on. Flickering in one room points to that circuit or a failing switch. Flickering across the whole house, or lights that dim when a big appliance starts, can mean a loose connection at the switchboard or a supply problem, and needs an electrician.

If you would rather have it checked, Ambient Electrical offers electrical fault finding in Sydney's Eastern Suburbs.

One light flickering

  • A loose or failing globe. With the light switched off, check it is seated properly, or swap in a globe you know works.
  • An LED on a dimmer that was designed for old incandescent or halogen globes. Many LEDs flicker or buzz on those dimmers. The fix is a dimmable LED and an LED-rated dimmer.
  • LED globes in old halogen downlights still running the original transformer. The transformer may not suit the LED's low load. Replacing it with a matched LED driver, or the whole fitting, fixes it.

Lights flickering in one room

If every light in one room flickers together, look at what they share: the switch or dimmer, and the circuit. A worn switch or a loose connection at the switch, or in a ceiling junction, will do it. That needs an electrician.

Lights flickering in the whole house

Flickering everywhere is more serious. Check first whether the neighbours are affected. If they are, it may be a network supply problem to report to Ausgrid on 13 13 88.

If it is only your home, the cause is often a loose connection at the main switch, a neutral fault, or a problem with your service mains, the cable from the street. Loose connections heat up, so this should be looked at soon, not left.

Lights dim when the air conditioner or oven starts

A brief dip when a large appliance starts can be normal. A deep or lasting dim, or one that is getting worse, can mean the circuit is overloaded, a connection is loose, or the installation is too small for today's appliances. Older homes built before air conditioning, electric ovens and pool pumps often need extra circuits.

Call an electrician now if

  • The flickering comes with buzzing, crackling or a burning smell
  • A switch, dimmer or light fitting is warm to touch
  • Lights flicker across the whole house and the neighbours are fine
  • It started after a storm or after work on your roof or walls

Sources

Ambient Electrical is an electrician in Waverley, Randwick and the Inner West, and works across Sydney's Eastern Suburbs.

Common questions

Why do my LED downlights flicker?

LED downlights usually flicker because the LED does not match the dimmer or the old halogen transformer it is connected to. A dimmable LED with an LED-rated dimmer, or a matched LED driver, fixes it.

Are flickering lights dangerous?

A single flickering globe usually is not dangerous. Flickering across a room or the whole house, or with buzzing, heat or a burning smell, can mean a loose connection, which can overheat. Have it checked.

Why are my lights flickering in the whole house?

If neighbours are affected, it may be the network supply. If only your home is, it is often a loose connection at the switchboard, a neutral fault or a problem with the service mains, which needs an electrician.

Why do my lights flicker when the air conditioner turns on?

A short dip is common when a big motor starts. A deep or worsening dip can mean an overloaded circuit or a loose connection and is worth an inspection.

Why are the lights flickering in only one room?

Flickering in one room points to that room's lighting circuit or a failing switch or dimmer, often an LED that does not suit the dimmer. It needs an electrician if it continues with new globes, or comes with buzzing, heat or a burning smell.

Source: energy.gov.au: Lighting.