Why Are My Lights Flickering?

Flickering lights are most often caused by a loose globe, an LED that isn't compatible with its dimmer, or a loose connection in the light fitting or switch. If only one light flickers, the cause is usually local and minor. If lights flicker across the whole house, or flicker when large appliances start, it can point to a problem with the switchboard, the main connection or the electricity supply, and should be checked by an electrician.

Start with the simple checks

Before assuming there's a wiring problem, rule out the easy causes:

• Loose globe: switch the light off, let it cool, and make sure the globe is seated firmly.
• Failing globe: swap in a globe you know works. LEDs and fluorescent tubes often flicker near the end of their life.
• Wrong globe for the fitting: some cheap LED globes flicker in fittings designed for halogen, especially with older transformers.

LED globes and dimmer switches

This is one of the most common causes we see. Older dimmer switches were designed for incandescent and halogen globes, which draw much more power than LEDs. When an LED is paired with an incompatible dimmer, you can get flickering, buzzing, a light that won't dim smoothly, or a faint glow when it's switched off.

The fix is usually to use LED globes marked as dimmable and replace the dimmer with one rated for LED loads. If you've recently switched to LEDs, this is the first thing to suspect. Our article on why lights buzz or hum covers the same issue from another angle.

Loose connections

If a light flickers when you touch the switch, when a door closes or when someone walks across the floor above, there may be a loose connection in the switch, the fitting or a junction box. Loose connections create resistance and heat, and over time they can damage cable insulation. This needs a licensed electrician, as the fix involves working on fixed wiring.

Flickering when appliances start

A brief dip in brightness when the air conditioner, oven, dryer or a pool pump kicks in is common, because large motors and heating elements draw a surge of current when they start. If the dip is noticeable every time, or getting worse, it can mean:

• the lights share a heavily loaded circuit with a large appliance
• a connection in the switchboard or on the main cable is loose or deteriorating
• the switchboard and wiring are struggling with modern loads

Whole-house flickering

When lights flicker in several rooms at once, the cause is usually upstream of the individual fittings. It could be a fault in the switchboard, a loose neutral connection, a problem with the service cable to the house, or an issue on the local network. Check with neighbours: if their lights are flickering too, report it to your electricity distributor. If it's only your property, have an electrician check the switchboard and main connections promptly, because a loose neutral can cause voltage swings that damage appliances.

Is flickering dangerous?

A single loose globe isn't. But flickering combined with any of the following is a reason to call an electrician straight away:

• a burning smell, or a light fitting or switch that's hot to touch
• buzzing or crackling from switches, fittings or the switchboard
• lights that get noticeably brighter as well as dimmer
• flickering together with breakers or safety switches tripping

If you smell burning, switch off the affected circuit at the switchboard if it's safe to do so. Our 24/7 emergency electricians cover metro Melbourne.

What an electrician will check

A licensed electrician will test the fitting, switch and dimmer, check connections at the switchboard, measure the supply voltage, and confirm whether the problem is a single fitting, a circuit or the incoming supply. In many cases the fix is a compatible LED dimmer or a tightened connection. Where older wiring or an overloaded switchboard is involved, they'll explain your options before any work starts. If you're upgrading lighting anyway, see our lighting design service.