Why Are My Lights Flickering When Appliances Are Running?

Flickering lights when appliances kick on are almost always caused by a voltage drop on the circuit, which happens when a large appliance draws a surge of current and temporarily starves other devices of power. In most cases the flicker lasts less than a second and is annoying rather than dangerous, but persistent or severe flickering can signal a serious wiring fault that needs urgent attention.

This article covers the most common causes of flickering lights in Sydney and NSW homes, how to tell a minor issue from a major one, and what a licensed electrician will do to fix it for good.

Understand Why Appliances Cause Voltage Drops

Every electrical appliance draws current when it starts up. Large motor-driven appliances like air conditioners, refrigerators, washing machines, and pool pumps draw a short but sharp spike of current called an inrush current during startup.

This inrush can be three to seven times the appliance’s normal running current. That sudden demand pulls voltage down briefly across the whole circuit, and your lights dim or flicker as a result.

In a well-designed electrical system with adequate wiring and a healthy switchboard, this flicker is barely noticeable and lasts under half a second. If the flicker is long, severe, or happens on circuits that should be unrelated, you have a bigger problem to investigate.

NSW homes built before the 1990s often have undersized wiring by today’s standards. Modern appliances are more powerful than those the original wiring was designed to handle, which is one reason older homes in Greater Sydney experience flickering more often.

Identify the Most Common Causes of Flickering Lights

Flickering lights triggered by appliances usually come down to one of several root causes. Knowing which one you are dealing with helps you decide how urgently you need an electrician.

• Overloaded circuit: Too many devices share one circuit, and there is not enough capacity for a large appliance to start without dragging down voltage.
• Loose wiring connections: A loose wire at the switchboard, at an outlet, or inside a junction box creates resistance. When current surges, that loose connection heats up and causes flickering or arcing.
• Undersized wiring: Old 1.5mm or 1mm cable runs cannot handle the current demand of modern appliances without significant voltage drop.
• Faulty switchboard or breaker: A worn circuit breaker or a failing main switch can struggle to deliver stable voltage when loads spike.
• Shared neutral wire issues: In older wiring systems, a shared neutral can cause voltage imbalances that create flickering across multiple circuits at once.
• Utility supply fluctuations: Sometimes the issue originates outside your home. Faults on the street-level network or neighbouring loads can push voltage outside the acceptable range of 230V plus or minus 10 percent under Australian Standard AS 60038.

Loose connections are the most dangerous cause on this list. Arcing at a loose terminal is one of the leading causes of house fires in Australia and should never be left uninvestigated.

Compare Flickering Scenarios to Gauge Severity

Not all flickering is equal. The table below helps you rate how urgent your situation is based on what you observe.

Flickering Pattern	Likely Cause	Urgency Level
Brief flicker when one appliance starts, then stable	Normal inrush current on a healthy circuit	Low. Monitor for worsening.
Flickering lasts several seconds after appliance starts	Overloaded or undersized circuit	Medium. Book an inspection soon.
Lights flicker on multiple circuits at once	Shared neutral fault or main switchboard issue	High. Call an electrician promptly.
Flickering even when no appliances are running	Loose connection or arcing fault	Very High. Stop using affected circuits and call now.
Flickering with buzzing sound or burning smell	Active arcing or overheating wiring	Emergency. Call 000 if you suspect fire risk.
Flickering when neighbours run appliances	Utility supply issue or shared transformer problem	Medium. Report to Ausgrid or Endeavour Energy.

If you are in the high or very high categories, do not delay. AJ Electrician Near Me handles urgent electrical inspections across Sydney and all of NSW, and our team can identify arcing faults before they escalate.

Understand What Happens During an Electrician’s Inspection

When a licensed electrician from AJ Electrician Near Me visits your home, they follow a systematic process to find the root cause of your flickering lights. Here is what that typically involves.

1. Visual switchboard inspection: The electrician checks for signs of heat damage, corrosion, loose terminals, and outdated components like ceramic fuse holders that no longer meet AS/NZS 3000 wiring rules.
2. Voltage measurement under load: Using a digital multimeter or power quality analyser, the electrician measures voltage at the switchboard and at affected outlets while appliances run to quantify the voltage drop.
3. Circuit load assessment: The electrician calculates the total load on each circuit against its rated capacity to identify overloading.
4. Thermal imaging (where needed): A thermal camera spots hot spots at connections that look normal to the eye but are arcing or overheating internally.
5. Wiring continuity checks: The electrician tests wiring runs to find resistance caused by damaged or undersized cable.

The inspection usually takes one to two hours for a standard home. Older homes or those with complex wiring may take longer. After the inspection you receive a clear diagnosis and a written quote for any repair work needed.

Review Typical Repair Costs in Sydney and NSW

Repair costs vary depending on what is causing the flickering. The table below gives realistic price ranges for the most common fixes in Sydney and the broader NSW market as of 2025.

Repair Type	Estimated Cost (AUD)	Notes
Electrical inspection and diagnosis	$120 to $250	Often waived if repair work is booked
Tighten loose connections at switchboard	$150 to $300	Quick fix, high safety value
Replace faulty circuit breaker	$180 to $350 per breaker	Includes parts and labour
Add a dedicated circuit for large appliance	$400 to $900	Depends on cable run length and switchboard space
Upgrade undersized wiring (per circuit)	$600 to $1,500	Higher in older homes with concealed runs
Full switchboard upgrade	$1,500 to $3,500	Required for homes with ceramic fuses or no RCDs

Sydney metro labour rates tend to sit at the higher end of NSW ranges. Regional NSW areas may see slightly lower labour costs but higher call-out fees if the job is remote. Always get a written quote before any work begins.

Know When to Call the Utility vs. an Electrician

Sometimes flickering lights are not caused by anything inside your home at all. The problem can originate on the street network managed by your local distributor, either Ausgrid in the Sydney metro and northern NSW, or Endeavour Energy in Western Sydney, the Illawarra, and southern NSW.

You may be dealing with a utility issue if:

• Your neighbours report the same flickering problem at the same time.
• The flickering happens randomly with no link to your own appliances.
• Your smart meter or energy monitor shows voltage consistently outside the 207V to 253V range that Australian Standard AS 60038 specifies.
• The problem started after recent street works or after a storm event that affected power lines in your area.

In these cases, report the issue to Ausgrid on 13 13 88 or Endeavour Energy on 13 10 13. They are required to investigate voltage quality complaints and restore supply within the standard range at no cost to you.

If the utility confirms their network is fine, the fault is inside your property and a licensed electrician must handle it. AJ Electrician Near Me can liaise with distributors on your behalf if the fault boundary is unclear.

Prevent Flickering with These Practical Steps

Once the immediate cause is fixed, a few practical measures reduce the chance of flickering returning.

• Give large appliances their own dedicated circuit: Air conditioners, ovens, dishwashers, and EV chargers should each run on a dedicated circuit to prevent startup surges from affecting lighting.
• Upgrade your switchboard if it is outdated: Homes in NSW with ceramic fuse holders or switchboards without safety switches (RCDs) do not meet current standards. An upgrade improves both safety and stability.
• Schedule a wiring audit every 10 years: Wiring degrades with age, heat cycles, and pest damage. A periodic audit catches problems before they become emergencies, especially in older Sydney suburbs like Parramatta, Leichhardt, or Newtown where homes date back decades.
• Use LED lighting: LED globes are less sensitive to small voltage fluctuations than older halogen or incandescent globes. Switching to LED can make minor voltage drops invisible.
• Avoid daisy-chaining power boards: Stacking multiple power boards on one outlet adds load and creates connection points that can loosen over time.

FAQs on Lights Flickering When Appliances Are Running

Is it normal for lights to flicker when the air conditioner turns on?

A very brief flicker of less than a second when a large air conditioner starts is considered normal because of the high inrush current the compressor motor draws. If the flicker lasts longer than one to two seconds or is severe, the circuit is likely overloaded or the wiring is undersized and an electrician should inspect it.

Can flickering lights cause a house fire?

Flickering caused by loose wiring or arcing connections is a direct fire risk. Arcing generates extreme heat at the fault point and can ignite nearby insulation or timber. If your flickering is accompanied by a burning smell, buzzing sounds, or discoloured outlets, treat it as an emergency and call a licensed electrician immediately.

Why do my lights flicker only at night?

Flickering that happens mostly in the evening often reflects peak demand on the local network. Many households run appliances simultaneously in the evening, which can push street-level voltage lower than usual. It can also indicate that your home’s wiring is marginal and only shows symptoms under higher loads. A power quality monitor can confirm whether the issue is inside or outside your home.

How do I know if the problem is in my switchboard or in the wiring?

A licensed electrician can determine this with voltage measurements and thermal imaging during an inspection. As a general guide, if the flickering affects only one circuit, the fault is usually in that circuit’s wiring or a downstream connection. If it affects multiple circuits, the switchboard or the main supply connection is the more likely culprit.

Can I fix flickering lights myself in NSW?

No. Under the NSW Electricity (Consumer Safety) Act and Australian Standard AS/NZS 3000, all electrical wiring work must be done by a licensed electrician. Touching switchboard connections, wiring terminals, or circuit breakers without a licence is illegal and extremely dangerous. You can replace a light globe yourself, but any investigation beyond that must involve a qualified tradesperson.

How long does it take to fix flickering caused by a loose connection?

Tightening loose connections at a switchboard typically takes under an hour once the electrician is on site. If loose connections exist throughout the wiring, for example at multiple outlets or junction boxes, the job takes longer. Your electrician will give you a time estimate after the initial inspection and diagnosis.

Wrap Up and Next Steps

Flickering lights when appliances run usually come down to inrush current, overloaded circuits, or loose wiring, and the fix ranges from a simple connection tighten to a full circuit upgrade depending on the cause. The key is to assess the severity honestly: brief, occasional flickers are low priority, but persistent or multi-circuit flickering needs professional attention as soon as possible.

AJ Electrician Near Me serves homeowners and businesses across Sydney and all of NSW with fast, thorough electrical inspections and repairs. Call us today on 1300 617 337 to book an inspection or request a quote, and we will get your lights stable and your home electrically safe.