Scorch marks, buzzing or a hot smell at the board?
Leave the breakers alone and, if you can reach it safely, turn off the main switch. If there's smoke or flame, get everyone out and call 000. A breaker that's hot, buzzing or discoloured shouldn't be reset again and again: get a licensed electrician to the board before that circuit goes back on.
Signs the breaker itself is the problem
- It won't stay on, yet the electrician finds nothing wrong on the circuit.
- It looks scorched or melted, or there's a hot plastic smell near the board.
- It's loose, cracked or no longer clicks firmly into place.
- The main switch is stiff, sparks when used, or is an old fuse-type switch.
Why a bigger breaker is never the fix
Every breaker is matched to the cable behind it. If a circuit trips because it's overloaded, a larger breaker simply lets the cable carry more than it was built for, and the first sign of trouble may be heat inside a wall. The real fixes are spreading the load, adding a circuit or finding the fault.
That's also why a good electrician asks why the old breaker failed before swapping it.
RCBOs: a safety switch for every circuit
Many boards have one or two safety switches, each guarding a group of circuits. When one trips, everything on it goes off, the fridge included. An RCBO protects a single circuit against both overload and earth leakage, so a fault in the garden lights leaves the kitchen running.
NSW Fair Trading recommends safety switches on every circuit, and RCBOs are a tidy way to get there. Consumer Affairs Victoria lists RCBOs alongside RCDs and RCCBs as acceptable safety switches for its rental standard. In Queensland an approved safety switch must trip at no more than 30 milliamps, and in Western Australia Building and Energy says at least two RCDs are the minimum.
The main switch
The main switch turns off the whole house. On older boards it may be a fuse-type switch rather than a circuit breaker. Western Power requires a circuit breaker main switch for new connections, when circuit capacity is added to an existing home, and for a 7 kW EV charger on a standard connection.
In New South Wales, work on the service protection device on the main switchboard, a customer-owned network device, is done by a Level 2 Accredited Service Provider. Elsewhere, the electrician will tell you who arranges that part.
Paperwork for a breaker swap
Even a like-for-like swap can need a certificate. In New South Wales a CCEW is required for any work on electrical equipment, like-for-like replacement included. Western Australia's Electrical Safety Certificate isn't required for maintenance or like-for-like replacement, and in the Northern Territory a certificate of compliance isn't needed when a fitting is swapped for a similar one that works the same way.
Moving to RCBOs or changing the main switch isn't like-for-like, so expect a certificate for that work.
What you can do from outside the board
You can
- Reset a tripped breaker once, with the appliances on that circuit unplugged.
- Press each safety switch's test button. Western Australia's Building and Energy suggests every three months.
- Label circuits as you learn which rooms each one covers.
- Note when it trips and what was running at the time.
Leave to a licensed electrician
- Replacing any breaker, RCBO, safety switch or main switch.
- Working out why a breaker failed in the first place.
- Adding circuits so heavy loads are properly spread.
- Testing and certifying the new protection.
Our view
If one breaker has failed and the rest of the board is sound, a straight replacement is fine. If an electrician is in the board anyway, we'd ask about moving to RCBOs at the same time, starting with the fridge and freezer circuit, so one faulty appliance can't cut power to the whole house overnight.
Want a specialist to sort it?
Tell us the job and your postcode. We match the licence-checked local electrician who does this kind of work, and they call you. No ring-around, and your number goes to them alone.