Written by H. Irwin Electrical | Published on June 2025
Intermittent electrical faults are most often caused by loose wire connections, corroded terminals, failing circuit breakers, or deteriorating insulation. These faults can be frustrating because they come and go, making them hard to pin down. This article walks you through the most common causes, warning signs to watch for, and what Adelaide homeowners should do when something feels off with their power.
Understand Why Intermittent Faults Are Harder to Diagnose
Unlike a complete power failure, an intermittent fault only shows up under certain conditions. It might happen when a particular appliance is running, when the temperature changes, or when vibration shifts a loose connection momentarily.
This is what makes them dangerous. Because the power often comes back on its own, many homeowners assume the problem has resolved itself. In reality, the fault is still there and getting worse with every occurrence.
Intermittent faults can cause arcing inside your walls, which is one of the leading causes of house fires. If your lights flicker, outlets stop working randomly, or your circuit breaker trips without an obvious reason, treat it seriously.
Identify the Most Common Causes of Intermittent Electrical Faults
There are several well-documented causes that electricians encounter regularly in Australian homes. Here is a breakdown of the most frequent culprits.
- Loose wire connections: Over time, terminal screws can loosen from vibration, heat cycling, or poor initial installation. A loose connection creates resistance, which generates heat and causes arcing.
- Corroded terminals and contacts: Moisture, salt air, and age cause oxidation on wire terminations and switchboard contacts. Corrosion increases resistance and causes intermittent contact.
- Failing circuit breakers: Breakers have a limited lifespan. An aging breaker may trip randomly, fail to trip when it should, or only make partial contact with the bus bar.
- Damaged or deteriorating cable insulation: Old wiring, particularly rubber-sheathed cable common in pre-1980s homes, can crack and allow conductors to touch intermittently.
- Overloaded circuits: Running too many high-draw appliances on a single circuit causes the breaker to trip, but it can also cause wiring to overheat and degrade over time.
- Faulty outlets or switches: The internal contacts inside power points and light switches wear out. A worn contact may work most of the time but fail under load or heat.
- Pest damage: Rodents and possums chew through cable insulation, creating shorts that may only activate when wiring moves or conditions change.
If you are in suburbs like Plympton, Marion, or Glandore and your home was built before 1980, loose or degraded wiring is a very real possibility. Older homes across these areas still have original electrical infrastructure that has never been updated.
Recognise the Warning Signs in Your Home
Knowing what to look and listen for helps you catch an intermittent fault before it becomes a serious hazard. Here are the most telling signs that something is wrong with your electrical system.
- Lights that flicker or dim unexpectedly, especially when an appliance switches on
- Power points that stop working for a period then come back without you doing anything
- A circuit breaker that trips repeatedly with no obvious cause
- A warm or discoloured power point or switch plate
- A burning smell, even if faint and brief, near outlets or the switchboard
- Appliances that reset or switch off randomly despite being in good working order
- A buzzing or crackling sound coming from inside a wall or ceiling
Any burning smell or audible crackling should be treated as an emergency. Turn off the circuit at the switchboard and call a licensed electrician straight away. Do not wait to see if it happens again.
Compare Common Fault Types by Symptom and Likely Cause
This table can help you match what you are experiencing with the most likely underlying cause. Keep in mind that only a licensed electrician can confirm the actual fault through testing and inspection.
| Symptom | Likely Cause | Urgency Level |
|---|---|---|
| Flickering lights on one circuit | Loose connection at the light fitting or switchboard | Medium |
| Whole house lights dim briefly | Loose neutral at the main switchboard or meter box | High |
| One outlet stops working randomly | Worn outlet contacts or loose wire at the back of the GPO | Medium |
| Circuit breaker trips without load | Failing breaker or cable fault on the circuit | High |
| Burning smell near switchboard | Arcing at a loose terminal or corroded busbar connection | Emergency |
| Buzzing sound inside wall | Arcing at a junction point or damaged cable | Emergency |
| RCD tripping intermittently | Moisture in a fitting, aging appliance, or cable insulation fault | Medium to High |
The H. Irwin Electrical team uses thermal imaging and circuit testing equipment to locate faults that are not visible to the naked eye. This is especially useful when a fault only appears under load or at certain times of day.
Understand How Adelaide’s Climate and Older Housing Stock Contribute
Adelaide’s climate plays a real role in electrical fault development. The combination of hot dry summers and cooler winters causes significant thermal expansion and contraction in wiring and switchboard components. Over many years, this cycling works terminal screws loose and stresses insulation.
Coastal suburbs like Glenelg, Glenelg North, Somerton Park, Henley Beach, and West Beach face an additional challenge. Salt air accelerates corrosion on exposed metal contacts, terminals, and switchboard components. Homeowners in these areas often experience faster degradation of electrical infrastructure than those further inland.
Many homes in Unley, Hyde Park, Kurralta Park, Prospect, and North Adelaide were built in the mid-to-late twentieth century. A significant number still have wiring that has never been upgraded. Rubber-sheathed cable, older ceramic fuse boards, and undersized circuits are still common in these areas.
If your home is more than 30 years old and has never had an electrical inspection, an intermittent fault is a strong signal that a broader assessment is overdue. H. Irwin Electrical regularly carries out switchboard and wiring inspections across these suburbs as part of routine safety checks.
Review What a Fault Diagnosis and Repair Typically Involves
When you call an electrician about an intermittent fault, here is what the process generally looks like. Understanding this helps you know what to expect and ensures nothing gets missed.
| Stage | What Happens | Typical Time Required |
|---|---|---|
| Initial consultation | Electrician gathers information about symptoms, frequency, and affected areas | 10 to 15 minutes |
| Visual inspection | Check switchboard, outlets, fittings, and accessible wiring for obvious issues | 30 to 60 minutes |
| Circuit testing | Use of multimeters and insulation resistance testers to identify faults | 30 to 90 minutes |
| Thermal imaging (if needed) | Detect hot spots at connections that indicate arcing or high resistance | 15 to 30 minutes |
| Fault repair | Re-terminating connections, replacing components, or upgrading wiring | 1 to 4 hours depending on scope |
| Final testing | Confirm the fault is resolved and the circuit is safe | 15 to 30 minutes |
Costs vary depending on the complexity of the fault and how accessible the wiring is. Simple fixes like re-terminating a loose connection might take an hour. Tracing a fault through in-slab or in-wall wiring can take considerably longer.
Always request a written quote before work begins. A reputable electrician will not pressure you to proceed without giving you a clear picture of what is involved and what it will cost.
FAQs on Intermittent Electrical Faults in the Home
Can I ignore an intermittent electrical fault if it only happens occasionally?
No. Intermittent faults do not resolve on their own and they tend to worsen over time. An occasional flicker or tripped breaker is an early warning sign of a fault that could lead to arcing, overheating, or a house fire if left unaddressed.
Why does my circuit breaker keep tripping with nothing plugged in?
A breaker that trips with minimal or no load is usually a sign that the breaker itself is failing, or that there is a wiring fault on the circuit such as damaged insulation causing a short. This needs to be inspected by a licensed electrician as soon as possible.
Is flickering lights always an electrical fault?
Flickering lights can sometimes be caused by a loose globe or a faulty LED driver, which are minor issues. However, if multiple lights flicker, or if it happens across different circuits, the cause is more likely a loose neutral connection or a switchboard fault, which is a serious issue.
How much does it cost to diagnose an intermittent electrical fault in Adelaide?
Diagnostic costs in Adelaide typically start from around $150 to $250 for a basic inspection, depending on how long it takes to locate the fault. Complex faults that require thermal imaging or extended testing will cost more. Your electrician should provide a quote once they have assessed the situation.
Can old wiring cause intermittent faults even if it has worked fine for years?
Yes. Wiring insulation degrades gradually, and faults can develop slowly over many years before becoming noticeable. Many Adelaide homes with 40 to 60 year old wiring appear fine until a connection finally fails or insulation cracks enough to allow a short to occur.
Do I need to be home when the fault is occurring for the electrician to find it?
Not necessarily. A good electrician uses testing equipment to identify faults even when they are not actively occurring. Providing a detailed description of when and how the fault shows up helps the electrician focus testing in the right areas.
Wrap Up and Next Steps
Intermittent electrical faults are rarely a minor inconvenience. They are usually a symptom of a real underlying issue, whether that is a loose connection, aging wiring, a failing breaker, or corrosion built up over years. The longer they are left, the greater the risk to your home and your family.
If you are in Glenelg, Somerton Park, Fulham, Beverley, Richmond, or anywhere across the Adelaide metro area and you have noticed anything unusual with your power, do not wait for the problem to get worse.
Contact H. Irwin Electrical today on 0432 270 757 to book a fault inspection. The team can assess your wiring, test your circuits, and give you a straight answer on what is going on and what it will take to fix it properly.
