Most electrical faults in Sydney homes follow predictable patterns. The housing stock in Greater Sydney — heavily weighted toward pre-1990 construction in inner-west, Hills District, Northern Beaches, and Eastern Suburbs suburbs — produces a specific set of recurring problems that licensed electricians see every week. Understanding what these faults look like, what causes them, and what they cost to fix helps you decide when to call and when an issue is urgent.

This is an overview of the faults our electricians encounter most often across Sydney. For general safety guidance, see our home electrical safety guide for Sydney homeowners.

1. Tripping Circuit Breakers

What it looks like: A circuit breaker in the switchboard trips (switches to the “off” or middle position) when appliances are in use. Resetting it allows the circuit to work briefly, then it trips again.

Common causes:

• Overloaded circuit — more appliances drawing current than the circuit is rated for (very common on older 10A kitchen circuits)
• Faulty appliance — a fault in a single appliance causing overcurrent on the circuit
• Short circuit in the wiring — active and neutral conductors making contact
• Worn circuit breaker that trips at below its rated current

What to do: Isolate the circuit by unplugging appliances one at a time. If the breaker holds once a specific appliance is removed, the fault is in the appliance. If it trips with nothing plugged in, the fault is in the wiring or the breaker itself — call a licensed electrician.

Urgency: Medium. Tripping breakers are inconvenient but the protection system is working. If a breaker is tripping repeatedly in the same 24-hour period, do not reset it again — isolate the circuit and call the next business day at the latest.

2. Safety Switch Tripping (Different from a Circuit Breaker)

What it looks like: A device labelled “safety switch” or with a “T” test button trips unexpectedly, cutting power to multiple circuits at once. This is different from a single circuit breaker tripping.

Common causes:

• Faulty appliance with an earth leakage fault (most common) — a damaged element, worn motor insulation, or cracked casing allowing current to reach earth
• Water ingress in an outdoor power point, garden circuit, or bathroom fitting
• Old wiring with degraded insulation that is leaking current to earth
• RCD nuisance tripping due to cumulative leakage across multiple appliances on the same RCD (common when an older group RCD covers many circuits)

What to do: Unplug all appliances on the affected circuits. Reset the safety switch. Plug appliances back in one at a time — when the switch trips again, the last appliance plugged in is the likely fault. Remove it from service and call the manufacturer. If the switch trips with nothing plugged in, call a licensed electrician.

Urgency: Medium (appliance fault) to high (if no appliance isolation resolves it — wiring fault).

For more detail on how safety switches work and why they trip, see our guide on what a safety switch is.

3. Flickering or Dimming Lights

What it looks like: Lights flicker briefly when a large appliance (air conditioner, washing machine, electric oven) starts, or lights in one part of the house flicker or dim without an obvious cause.

Common causes:

• Loose connection at the light fitting, switch, or in the wall — by far the most common cause in older homes
• Voltage drop from high-draw appliances starting on the same circuit
• Faulty light switch with a worn mechanism
• Poor neutral connection at the switchboard (affects multiple circuits simultaneously)
• Intermittent fault in the network connection (contact Ausgrid or Endeavour Energy if neighbours are also affected)

What to do: If flickering is isolated to one light or fitting, start with the light switch and globe. If it is across multiple lights in the same room or circuit, the connection is likely upstream — at the switch, in the ceiling rose, or at the junction between circuits. Loose connections in older homes can eventually cause arcing and are a fire risk. Call a licensed electrician if the fault persists after changing the globe.

Urgency: Low to medium. Persistent flickering that you cannot trace to a single globe should be investigated within a week.

4. Power Points That Are Warm, Discoloured, or Sparking

What it looks like: A power point feels warm to the touch, has visible discolouration or scorch marks around the face plate, sparks when you plug something in (more than the normal brief flash), or makes an audible buzzing or crackling sound.

Common causes:

• Loose internal connection — the most common cause of heat and sparking at power points
• Overloaded power point from an extension lead or power board running too many appliances
• Worn power point contacts that no longer make a solid connection with plug pins
• Previous DIY work with non-standard connections

What to do: Stop using the power point immediately. A warm or discoloured power point represents a potential fire risk. Turn off the circuit at the switchboard if you are unsure whether the power point is still live. Call a licensed electrician.

Urgency: High. Warm or sparking power points should not be deferred.

5. Power Points with No Earth (Older Homes)

What it looks like: Power points in older homes that only have two holes (active and neutral) rather than three — meaning there is no earth connection. Or three-pin power points installed in place of two-pin outlets where the earth pin is connected to nothing.

Common causes:

• Two-wire wiring systems without an earth conductor, common in Australian homes built before approximately 1966
• Rewiring that missed some circuits
• Upgrades from two-pin to three-pin power points carried out without running a new earth conductor

What to do: Confirm the situation with a licensed electrician. Two-wire systems without earth are legal to leave in place in existing owner-occupied homes that are not otherwise undergoing electrical work — but they represent a genuine safety risk. The practical options are running a new earth conductor to individual circuits or upgrading the switchboard and rewiring, depending on the extent of the issue.

Urgency: Low to medium for existing installations. High if you are planning any electrical work on the property — new work must meet current standards.

6. No Power in One Area of the House

What it looks like: Power points and lights in one room or area of the house stop working. Other circuits are unaffected.

Common causes:

• Tripped circuit breaker — check the switchboard first (look for a switch in the middle or “off” position)
• Tripped safety switch — similar check
• Blown fuse in a ceramic fuse board
• Broken conductor in the wiring between the switchboard and the circuit
• Faulty circuit breaker that has failed open (circuit dead even though the breaker appears to be on)

What to do: Check the switchboard. If you can identify and reset a tripped breaker, do so. If the breaker trips again immediately or the power does not come back after resetting, call a licensed electrician. Do not replace fuses in a ceramic fuse board with wire, foil, or a higher-rated fuse — this removes the overcurrent protection from the circuit.

Urgency: Low (tripped breaker, isolated) to high (complete circuit failure with no obvious cause).

7. Switchboard Buzzing or Humming

What it looks like: An audible humming, buzzing, or crackling sound coming from the switchboard, either continuously or intermittently.

Common causes:

• Loose busbar connection — the most serious cause; the busbar is the central conductor inside the switchboard and a loose connection here can cause arcing
• Worn or failing circuit breaker
• Normal transformer hum from a relay or meter (some buzzing is normal at very low levels; loud or intermittent buzzing is not)

What to do: A buzzing or crackling switchboard is an emergency electrician call. Do not open the switchboard yourself. If you can smell burning or see discolouration on the switchboard exterior, turn off the mains at the main switch and call immediately.

Urgency: High. Call Landmark Electrical on 0405 091 456 for 24/7 response.

For 24/7 emergency electrical response in Sydney, see our emergency electrician page.

8. Hot Water System Trips or Fails

What it looks like: The electric hot water system stops producing hot water. A dedicated circuit breaker for the hot water system may be tripped.

Common causes:

• Failed element — the heating element has burnt out
• Tripped thermal cut-out — a safety device inside the hot water system that trips if the water temperature exceeds a threshold; resettable in most cases
• Faulty thermostat
• Tripped dedicated circuit breaker

What to do: Check the circuit breaker for the hot water system at the switchboard. If it has tripped, reset it — if it holds and the hot water system comes back, the problem may have been a power surge. If the circuit breaker trips again or the element does not heat, an electrician is needed to replace the element or thermostat.

Urgency: Medium. No hot water in winter requires prompt attention; the fault itself is not typically a safety issue.

9. Outdoor or Pool Circuit Faults

What it looks like: Lights or power points in the garden, driveway, or around a pool stop working, or the safety switch trips when outdoor circuits are in use.

Common causes:

• Water ingress in outdoor power points or weatherproof fittings that are no longer adequately sealed
• Damaged underground cabling (from digging, root intrusion, or cable degradation)
• Faulty pool pump or equipment causing earth leakage
• Corrosion in outdoor fittings over time

What to do: Outdoor and pool electrical faults can be serious — earth leakage into pool water or a wet garden environment creates a real electrocution risk. Do not attempt to reset safety switches repeatedly for outdoor circuit faults without identifying the cause. Call a licensed electrician.

Urgency: Medium to high depending on the circuit. Pool electrical faults are high — pool water conducts electricity and the consequences of a fault can be severe.

10. Burning Smell from a Fitting, Outlet, or Switchboard

What it looks like: A smell of burning plastic or a hot electrical smell, either from a specific fitting or power point, or from the switchboard area.

Common causes:

• Arcing at a loose connection — can ignite surrounding insulation or timber
• Overloaded wiring or fittings generating heat beyond what the insulation can tolerate
• A failing appliance that is overheating internally

What to do: This is an emergency. Turn off the affected circuit at the switchboard (or the main switch if you cannot identify the circuit). Do not use the power point or fitting again until a licensed electrician has inspected it. If the smell is from the switchboard or you cannot locate the source, turn off the main switch and call an emergency electrician immediately.

Urgency: Critical. Call 0405 091 456 24/7.

When to Call an Emergency Electrician vs Wait for Business Hours

Book an Electrical Fault Diagnosis with Landmark Electrical

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Call 0405 091 456 or book online. For emergency electrical faults, call directly — our phones are answered 24 hours a day, 7 days a week.