Preventing electrical fires at home: common causes and simple habits

Electricity makes heat wherever it meets resistance. In a sound installation that heat is small and spread out. A fire starts when heat builds up in one spot faster than it can escape: a terminal that's worked loose, a cable carrying more than it should, a heater element against a curtain, or a cord with broken strands inside its insulation.

Energy Safe Victoria says fire brigades respond to more than 300 domestic electrical fires each year, many caused by old wiring that has degraded or can't cope with modern equipment. CFA's Chief Officer said in June 2024 that more than 140 of the 780 residential structure fires CFA attended the previous year were caused by electrical equipment, including appliances and air conditioning.

The causes fall into four broad groups: the fixed wiring, overloading, heat-producing appliances and damaged cords. Each has its own warning signs and its own fixes.

Old cable insulation hardens and cracks, especially rubber-insulated wiring and cable that has spent decades in a hot roof or beside old halogen downlights. Connections at switches, points, light fittings and the switchboard loosen as they heat and cool through years of use, and a loose connection makes its own heat, which loosens it further.

None of this trips a breaker. A circuit breaker responds to too much current and a safety switch to current leaking to earth, and a connection running hot at normal current triggers neither. Energy Safe Victoria notes that safety switches may not protect all wiring and appliances. The warning signs are the ones you notice: a warm or discoloured switch plate, a fishy or burning smell, buzzing, or lights that flicker.

Energy Safe Victoria says that when buying a home built before the 1980s, it's imperative to have the wiring checked before moving in. Our guide to old house wiring covers how to recognise what you have, and our guide to downlights, insulation and fire risk covers the roof space.

A power point and the cable behind it are designed for a certain load. A power board doesn't add capacity; it shares one point between more plugs. Run a heater, kettle and toaster through one board and the board, the plug and the point all run hot. Plug one board into another, or into an extension lead, and the risk compounds.

Extension leads are made for temporary use. A lead permanently feeding the shed, the garage fridge or a heater in the study is doing the job of fixed wiring, and a lead left coiled on its reel heats up when it carries a big load. If a room depends on boards and leads, it needs more power points, or a heavy appliance needs a circuit of its own.

It happens at the switchboard too. Homes that have added split systems, an induction cooktop and an EV charger to circuits designed decades ago can push old cable and connections past what they were built for.

Appliances that are meant to get hot start fires when something burnable gets too close. Portable heaters near bedding, curtains or clothes drying on a chair are the classic winter case. Figures compiled by CFA and Fire Rescue Victoria show winter had the highest number of preventable residential fire deaths in Victoria in 2025.

Clothes dryers are another. Lint is fine, dry and burns readily, and it collects in the filter, around the drum and behind the machine. Clean the filter every load, keep the back of the dryer clear, and don't leave it running when you go to bed or go out. Toasters, irons and hair straighteners need a clear, hard surface and switching off when you walk away.

Rechargeable batteries are a newer risk. E-scooter, e-bike and power tool batteries, and cheap chargers, can overheat while charging. Charge them on a hard surface away from anything that burns, use the charger made for them, and don't leave them charging unattended for hours.

A cord that's been shut in a door, crushed under furniture, run under a rug or bent sharply at the plug can break strands inside while the outside looks fine. Fewer strands carrying the same current means more heat in that spot, and a cord under a rug can't shed it.

Check cords when you plug things in. Cracks, kinks, flattened sections, scorch marks or a plug that feels warm all mean the appliance should be repaired by a qualified repairer or replaced. Tape is not a repair.

Most of the risk comes down to a handful of habits. None of them costs anything, and together they deal with the common causes.

Add a look at the switchboard twice a year. Scorch marks, buzzing, melted plastic or a hot smell there mean close the door, keep people away and get an electrician. If there is smoke, fire or immediate danger, get everyone out, and never put water on an electrical fire.

If a fire does start, working smoke alarms buy the time to get out. The Building and Plumbing Commission says they're compulsory on or near the ceiling of every storey, between each bedroom area and the rest of the house, and advises replacing them generally after ten years. Fire Rescue Victoria says to test them monthly by holding the test button until the alarm beeps three times.

Surge protection guards equipment rather than people. Energy Safe Victoria explains that a switchboard surge diverter captures voltage spikes that would otherwise pass into your appliances, and that surge diverters and circuit breakers don't protect people from electric shock. That's the safety switch's job.

In an older home, a periodic electrical safety check finds the loose connections, failing insulation and overloaded circuits you can't see. Good times to book one are after buying, before renovating, or when anything on the habits list keeps recurring.