A breaker trips when the current through it exceeds what it's rated for — that's either an overloaded circuit, a short circuit, or a fault in the breaker itself. If it trips the instant you flip it, before any load is even drawn, a short circuit is the most likely cause, and you shouldn't keep resetting it repeatedly.
Possible causes
- Circuit overload — too many high-power appliances running on the same outlet group at once
- A short circuit in the wiring, an outlet, or inside one of the connected appliances
- A high inrush current when switching on heavy equipment — a fridge, washing machine, electric kettle
- A worn or faulty breaker itself — a sticking mechanism or loosened internal contacts
- A breaker installed with a rating too low for the circuit's actual load
- Current leakage from damaged insulation or moisture — relevant if it's an RCD or an RCBO rather than a plain breaker
Why it matters
Repeatedly resetting a breaker that's tripping because of a short circuit lets the wire at the fault point heat up a little more each time — that's a direct path to melted insulation and fire. Flipping it back on "just in case" over and over doesn't fix anything, it just wears the breaker's contacts and raises the risk.
If the cause is a plain overload, the risk is lower, but wiring that's constantly running near its limit still ages faster and can lead to hot connections over time.
What to do
When you need an electrician
Call an electrician if the breaker trips instantly with no load, trips again after you've unplugged everything, or if you smell burning or see melted plastic. Swapping in a higher-rated breaker yourself without checking the wiring is dangerous — the circuit may not be able to handle the extra load.
Frequently asked questions
Can I just install a higher-rated breaker so it stops tripping?
No, that's dangerous. A breaker's rating is chosen to match the wire's gauge and safe current capacity, not the number of appliances you'd like to run. An oversized breaker may fail to trip in time during an overload or short circuit, letting the wires overheat and melt unprotected.
The breaker only trips when I turn on the kettle or a heater — why?
The circuit is most likely overloaded: kettles and heaters draw a lot of current, and if anything else on that same group is already running, the combined load exceeds the breaker's rating. A loose-contact outlet or extension cord can also be the culprit.
The breaker trips at night when nothing is switched on — is that normal?
No, that points to a hidden fault — a short circuit in a damp spot, damaged insulation, or a defective breaker. It needs an on-site diagnostic, not a wait-and-see approach.