Why Are My Lights Flickering? 7 Causes, Ranked by How Serious They Are

Byron Knight, Licensed Electrical Contractor

QLD Lic. 1511406 · 20+ years’ experience · Gold Coast & SEQ · Updated November 2026

Most flickering is harmless. Some of it is an early warning sign of a fault that can start fires inside wall cavities. The frustrating part is that from where you’re standing they look the same: a light that won’t sit steady.

Below, the causes are ranked by how serious they are, along with the one detail that tells you roughly where in the system your fault sits before anyone opens anything up.

First: the pattern tells you where to look

Before working through causes, note which lights are flickering. This single observation narrows the field more than anything else you can do without test equipment.

The third row is the important one. Whole-house flickering is not a bigger version of one-light flickering. It’s a different problem, and its most serious cause is at the bottom of the list below.

The 7 causes, least to most serious

Ranked by risk of harm, not by how often each turns up. The common ones sit at the top; the dangerous one sits at the bottom.

1. Loose or failing globe. A common cause and the easiest fix. Globes can work loose as the fitting heats and cools. If it’s one light, turn it off, let it cool, and reseat or replace the globe. If the flicker stops, you’ve likely found it.
2. Incompatible dimmer. Dimmers installed for halogen loads often don’t suit LED drivers, producing flicker, buzzing, or a narrow usable dimming range. Annoying rather than hazardous; more on this in halogen versus LED downlights.
3. Failing LED driver. Integrated LED fittings have a driver that eventually fails, sometimes flickering for weeks before it goes entirely. A component at end of life, not a wiring fault, though on an integrated fitting it usually means replacing the whole unit rather than a globe.
4. Voltage dip when a large appliance starts. Air conditioners, pool pumps and washing machines draw extra current on startup, and a brief slight dim as they kick in can be normal. What isn’t normal is a pronounced dip, a long one, or one getting worse over time. That suggests the circuit is closer to its limits than it should be.
5. Supply-side voltage fluctuation. Sometimes the instability comes from the network, not your property. See the section below for the limits and who to call. A quick check: ask a neighbour whether they’re seeing it too.
6. Overloaded circuit. Too much load on one circuit produces voltage sag under demand, and sustained overloading generates heat in the wiring. Rarely an emergency today, but a problem eventually, and a switchboard inspection will show whether a circuit is carrying too much. It often shows up alongside breakers tripping, and it’s a common trigger for a switchboard upgrade.
7. Loose neutral or degraded connection. The serious one. A loose or deteriorating neutral destabilises voltage across everything downstream, and the loose joint itself can arc, generating local heat capable of damaging insulation and igniting surrounding material. It typically shows up as flickering across multiple rooms at once, often with appliances behaving strangely at the same time. This needs an emergency electrician now, not at the next convenient appointment.

Why a loose neutral is the one worth understanding

The neutral is the return path for current. When that connection degrades, through a corroded terminal, a screw that’s backed off over years of heating and cooling, or a joint that was never quite tight, the current still flows, but unstably. Voltage downstream swings up and down, which is what you see as flicker.

Two things make it serious, not just annoying. The loose joint can arc, and arcing concentrates heat right where the wiring insulation is trying to do its job, the same kind of mechanism behind a switchboard that buzzes or hums. And the voltage instability it creates can push appliances outside their design range, which is why a loose neutral can show itself through electronics behaving oddly rather than through the lights alone.

The tell is things happening at the same time. A fridge cycling off and restarting, a TV rebooting, a microwave losing its clock, all at the same moment the lights dip. People usually file these as three separate annoyances. Happening together, they can point to one upstream fault.

Heating and cooling is also why the fault can be intermittent and hard to pin down: connections expand when warm and contract when cool, so a marginal joint can behave for days and then misbehave on a hot afternoon. That’s not a reason to wait and see whether it settles. It needs test equipment, not observation.

If there’s a burning smell involved, treat that as the priority signal. What to do about a burning smell from a power point covers the immediate steps, and if there’s smoke or fire, call 000.

When it’s the supply, not your wiring

Since 27 October 2018, Queensland’s Electricity Regulation has set the standard low-voltage supply by reference to the nominal voltage in AS 60038. Before that it was 240 V with a 6% tolerance. For a 230 V nominal supply, the band commonly quoted from that standard is roughly 216 V to 253 V.

Supply drifting outside that band is a network issue, not a fault in your installation, and no amount of work inside your switchboard will fix it. On the Gold Coast that’s Energex, on 13 62 62. If a neighbour is seeing the same thing, that’s a strong sign the problem is on the network side.

What you can safely check yourself

1. Note the pattern: one light, one room, or multiple rooms. Write down what else is running when it happens.
2. Reseat or replace the globe. Turn the light off, let it cool, then try it. If the flicker stops, that was it.
3. Run a dimmed light at full brightness for a while. Flicker that only appears when dimmed points to dimmer compatibility rather than wiring.
4. Ask a neighbour. If they’re seeing it too, it’s likely supply-side and worth reporting to Energex.

Anything beyond that, like opening fittings, testing connections or touching the switchboard, is licensed work and not worth attempting. The line is the same as anywhere else in a Queensland home: globe changes are yours, anything involving fixed wiring isn’t, as set out in what you can legally do yourself.

What we check when flicker has no obvious cause

Intermittent flicker is fault finding and troubleshooting work. What that can involve:

• Voltage measurement under load: confirming supply sits in the correct range, and watching what it does when demand changes
• Thermal inspection of switchboard connections: a degrading connection can run hot before it fails, which is what a thermal scan can find
• Neutral integrity testing: checking the return path across circuits rather than assuming it
• Circuit loading assessment: whether the affected circuit is carrying more than it should
• Physical inspection of connections at fittings, switches and the board itself

Intermittent faults are among the hardest to diagnose, precisely because they’re often not misbehaving at the moment someone’s looking at them. That’s what the test equipment is for. Related symptoms worth ruling in or out: no power in one room, or power points dead with the lights still on.

On the Gold Coast, specifically

Two patterns are worth knowing here. Coastal air corrodes connections, so in beachside homes through Palm Beach, Currumbin and Mermaid Beach, a marginal joint can deteriorate sooner than it would inland, the same mechanism as switchboards corroding faster near the water.

The other is seasonal. Storm season brings network disturbances and surges, so house-wide flicker during a storm that clears when the weather does is often the network. House-wide flicker that continues after the storm passes needs checking, and that distinction is worth holding onto.