A breaker that trips is not faulty. It is a protective device operating exactly as intended, and the useful question is what it is protecting against.
Work out which kind of trip it is
There are broadly three causes: too much load on a circuit, a genuine fault in the wiring or an appliance, or accumulated earth leakage across several circuits.
Narrowing it down yourself
- Note which device trips — a single breaker, an RCD, or the main switch. That alone tells an electrician a great deal.
- Unplug everything on the affected circuit, reset, and plug items back one at a time. A failing appliance is the most common cause by a wide margin.
- Notice the pattern. Does it happen when it rains, when the shower runs, when the washing machine heats?
When to stop and call somebody
If there is a burning smell, scorch marks, a buzzing sound from the board, or anything has given somebody a shock, stop. Do not keep resetting it — repeatedly resetting a breaker into a fault is how a fault becomes a fire.
What we will do
Divide the installation and test section by section until the fault is isolated. That is slower than swapping parts and far cheaper than replacing working ones.