You walk into the kitchen, flip the switch, and instead of a steady glow you get a faint pulse. Or the downlights hold steady all night, until the fridge or the air-con kicks in and the room dims for a heartbeat. Most flicker is harmless and there is a five-second fix. Some flicker is the early warning before something more serious. The trick is knowing which is which.
Read this first if every light in the house flickers at once. Whole-house flicker is the one that needs the real attention. It almost always means there is a loose neutral somewhere between your switchboard and the network, and it can push the voltage up and down enough to damage appliances or start a fire inside a wall. Stop using high-draw gear, do not keep flipping switches, and call an electrician same day.
What Flickering Actually Tells You
A steady light needs a steady voltage. When the voltage dips, even briefly, the bulb dims. When the voltage swings up, it brightens. So flicker is the visible sign that something in your wiring, your fitting, your appliance, or your supply has a problem holding the voltage steady.
The useful bit is that where the flicker happens tells you where the fault is. One bulb flickering on its own usually means the bulb or the fitting. One room flickering means that circuit. Half the house dimming when the dryer starts up means an overloaded or undersized circuit. The whole house flickering at the same time means the supply or the switchboard, and that is the serious one.
So before you go down a rabbit hole, walk through the rooms that are affected. The pattern points at the cause.
The 6 Most Common Causes (Ranked)
In a typical Northern Beaches home, the cause of flickering lights almost always sits inside one of these six buckets. They are ordered from most to least common based on what we actually find on callouts.
A Loose or Failing Bulb
Easily the most common cause and the cheapest to fix. The bulb has worked itself loose in the socket, or the bulb itself is on its way out. With LEDs, the driver inside the bulb is the usual failure point, especially with cheap globes from a supermarket bin.
It can also be a mismatch. LED bulbs paired with an older trailing-edge dimmer that was designed for halogens will hum, flicker, or refuse to dim properly. The fix is either a compatible LED dimmer or LEDs marked as dimmable for your switch type.
Verdict: Try the bulb test below. Often a two-dollar fix.A High-Draw Appliance Starting Up
Anything with a motor or a heating element draws a sudden surge of current the moment it turns on. Fridges, air-conditioner compressors, pool pumps, washing machines, and electric ovens are the usual suspects. That surge briefly pulls the voltage down across the rest of the circuit, and your lights blink as it happens.
A barely-there flicker that lasts the blink of an eye is usually fine. A clear, lingering dim every time the air-con kicks in, or one that makes the TV reset, means the circuit is undersized for the load it is carrying or there is a poor connection somewhere along it.
Verdict: If it is brief, ignore it. If it is obvious or repeated, get it looked at.A Loose Connection at a Fitting or Power Point
Inside every light fitting, switch, and power point there are screw terminals holding the wires in place. Over time, especially with thermal cycling from the heat of older halogen downlights, those screws can work loose. A loose terminal arcs, and an arc shows up as a flicker. It also runs hot, which is the part that matters.
This is usually the cause if the flicker is in one fitting, gets worse over weeks, or you notice a faint buzz, warmth, or discolouration around the switch plate or socket. It needs a sparky, and sooner rather than later. A loose connection that has been left long enough to brown the plastic is one of the leading causes of electrical fires inside walls.
Verdict: Diagnostic visit, usually a quick fix once located.An Overloaded or Undersized Circuit
Most circuits in homes built before the mid-2000s were sized for a much lighter electrical lifestyle. A kitchen circuit that comfortably ran a kettle and a toaster in 1995 is now also running a benchtop oven, an induction kettle, a coffee machine, a dishwasher, and an EV charger that wandered too close. When the total load gets close to the circuit's limit, voltage starts to sag and lights dim.
If the flicker correlates with specific high-draw appliances all running at once, especially in the kitchen, laundry, or wherever the air-con is, the circuit is the bottleneck. The fix is usually a redistribution of loads across circuits and sometimes a switchboard upgrade. See our guide on the signs a switchboard needs upgrading for the bigger picture.
Verdict: Circuit redistribution, sometimes a switchboard upgrade.Corroded Connections in the Switchboard or Wiring
This is the one with the strong Northern Beaches flavour. Salt-laden coastal air gets at the terminals inside older switchboards and at outdoor power points, and slowly corrodes the metal. Corroded contacts have higher resistance, that resistance creates heat, and the connection starts to behave inconsistently. The visible symptom is flickering, often on more than one circuit, sometimes intermittent for weeks before it gets serious.
We see this in older boards in suburbs sitting closest to the water like Manly, Queenscliff, Curl Curl, Collaroy, Avalon and Newport, particularly in homes that still have a 1980s or earlier ceramic-fuse switchboard. If you have flickering on multiple circuits and your switchboard predates the mobile phone, this is a likely culprit. A licensed electrician with a thermal camera and insulation resistance tester will find the affected connections in a single visit.
Verdict: Switchboard inspection and tightening or rebuild. Coastal homes due a check every 5 to 10 years anyway.A Loose Neutral (The Serious One)
Last on the list because it is the rarest, but the most important to recognise. The neutral conductor is the one that returns current to the network. If the connection on the neutral has come loose, either inside your switchboard, at the main service connection on the side of the house, or out on the Ausgrid pole, the voltage across your circuits starts to swing wildly. Lights on one side of the house brighten while lights on the other side dim. Appliances die. Wiring inside walls heats up.
The unmistakable sign is whole-house flicker, often dramatic, often combined with appliances misbehaving (TVs resetting, fridges making odd noises, LED globes glowing when switched off). If you see this, do not keep using the place as normal. Turn off the main switch at the board if you can do it safely, ring an electrician immediately, and let Ausgrid know if neighbours are seeing the same thing.
Verdict: Same-day callout. Genuine emergency.The 5-Minute Self-Check
Before you ring anyone, run this. About half of flickering-lights jobs get solved without an electrician coming out. The catch is doing it in order. Skip a step and you will just confuse yourself.
- Tighten or swap the bulb. Turn the light off, let it cool, and check it is screwed all the way in. If it is loose, that is your fix. If it is tight, swap it for a known-good bulb of the right type and wattage. If the flicker stops, the bulb was on its way out. If it keeps flickering, the fitting or the circuit is the issue.
- Check the pattern. Is it one fitting, one room, one side of the house, or every light at once? Walk through and note it. One fitting points at the fitting. One room or area points at the circuit. The whole house points at the switchboard or the supply, and that is the serious one.
- Watch for a trigger. Does the flicker happen at random, or every time the air-con, fridge, washing machine, or dryer kicks in? A trigger means a circuit issue. Random flicker means a fitting or a loose connection. No trigger plus whole-house flicker means the supply.
- Test your dimmer compatibility. If the flickering is on a dimmer switch with LED globes, check the globe box for "dimmable" and check that the dimmer is rated for LED. Old halogen dimmers and LEDs are a common cause of nuisance flicker.
- Stop and call if any red flags are showing. Whole-house flicker, a burning smell, a warm or discoloured power point, a buzzing switchboard, or appliances dying unexpectedly all mean it is time to stop testing and ring a sparky. Same day.
If the bulb and pattern tests do not solve it, the fault is in the fixed wiring, a fitting, the switchboard, or the supply. That is a sparky job. The right tools (insulation resistance tester, thermal camera, multimeter) find the affected circuit and location, usually inside the first hour of a callout.
When to Call an Electrician Same Day
Most flickering lights can wait a day or two. Some cannot. Here is the line.
Call same-day if any of these are happening
- Every light in the house flickers at the same time
- Lights on one side of the house get brighter while others dim
- You can smell burning plastic, hot metal, or anything smoky near a switch, socket, light fitting, or the switchboard
- A power point, switch, or fitting feels warm to the touch or has gone yellow or brown
- You hear a buzzing or crackling from the switchboard or any fitting
- Appliances are resetting, behaving strangely, or dying earlier than they should
- LED globes glow faintly even when the switch is off
Can wait a day or two if
- The flicker is on a single bulb or fitting, with no smell, no heat, no buzz
- A new dimmer or LED globe started flickering after you swapped them in, with no other symptoms
- The flicker is brief and only happens at the moment a fridge or air-con starts up
- You have identified one faulty appliance and just want it confirmed by a sparky
If you are not sure, ring us. We would rather walk you through a quick check on the phone than charge you for a visit you did not need.
What to Expect When You Call
Diagnosing flickering lights is rarely the expensive part of a job. Most of the cost sits in the fix itself, and most fixes are quick once the cause is found.
Here is the general shape of a callout:
- Free over-the-phone advice first. Tell us what you are seeing. Often we can walk you through the bulb and pattern test, save you a callout, and only book a visit if it actually needs one.
- Same-day visits where possible. Most Northern Beaches suburbs sit within 20 minutes of Oscar. Genuine emergencies (whole-house flicker, burning smell, vulnerable occupant) get priority.
- Diagnostic first, fixed price second. Insulation resistance testing, thermal imaging at the switchboard, and circuit isolation find the fault in most homes inside the first hour. Once we know what it is, you get a fixed price before any work starts.
- No surprises. The price is locked before the tools come out. Bigger jobs (switchboard upgrades, full circuit rewires) get quoted separately after the diagnostic, also as a fixed price. See our tripping safety switch guide if your flicker also comes with the RCD letting go.
Call 0421 755 198 for a free over-the-phone chat. We will tell you straight whether it is something you can sort yourself or whether it needs a sparky.
How to Stop It Happening Again
Once the fault is fixed, a few habits keep the lights steady.
- Stick to decent LED globes. The cheap supermarket ones flicker, hum, and die early. A quality globe from a hardware store lasts longer and behaves better with most dimmers.
- Match the dimmer to the globe. If you are using LEDs on a dimmer, the dimmer needs to be rated for LED. Old halogen dimmers and LED globes are the most common cause of new-build flicker.
- Do not pile high-draw appliances on one circuit. A kettle and a toaster on the kitchen circuit is fine. Add an induction cooktop, an oven, and a dishwasher and you are asking for it. Spread the load, and if you cannot, add a circuit.
- Get the switchboard checked at every safety inspection. Loose terminals are easier to find before they start arcing. Our electrical safety inspection guide walks through the timing and what gets checked.
- For coastal homes, get an inspection every 5 to 10 years. Salt air does not stop. The boards and outdoor sockets in Manly, Collaroy, Avalon and similar suburbs benefit from a periodic check, and it is cheaper than a fault callout.
The Quick Summary
Flickering lights are almost always a real fault, not a quirk. The fault is usually a loose bulb (most common), a high-draw appliance starting up, a loose connection at a fitting, an overloaded circuit, salt-corroded switchboard terminals, or in the worst case a loose neutral on the supply. The 5-minute self-check resolves about half of all cases. If the test does not find it, a licensed electrician with the right tools will, usually inside the first hour of a callout.
Connery Electrical handles flickering-lights callouts across the Northern Beaches every week. We answer the phone, we tell you what is likely wrong before we come, and we sort it in one visit where we can. See our emergency electrician service for same-day work, or our residential electrician page for planned bookings.
