A breaker that trips once is doing its job. One that trips again and again is telling you something, and the trick is working out what without taking risks.
First, know what tripped
Open the consumer unit (the fuse box) and look at which switch has dropped:
- A single breaker (MCB) protects one circuit: the kitchen sockets, the lights upstairs. If one of these trips, the problem lives on that circuit.
- The RCD protects several circuits at once against earth leakage. If the RCD trips, something connected to any of its circuits may be leaking current. Often that’s a faulty appliance, sometimes moisture.
A safe way to narrow it down
- Switch off and unplug everything on the affected circuit, including the innocent-looking things like phone chargers and the fridge.
- Reset the breaker or RCD. If it holds, the wiring is probably fine and one of the things you unplugged is the culprit.
- Plug items back in one at a time, waiting a moment between each. When the trip happens again, you’ve found your suspect. Stop using that appliance.
- If it trips with nothing plugged in, the fault is likely in the fixed wiring or a fitting. That’s the point to stop resetting it and call an electrician.
Never hold a breaker closed, tape it on, or swap it for a bigger one. Repeated tripping with no obvious appliance cause can mean a damaged cable, water ingress or a deteriorating installation. Those want finding, not overriding.
When the board itself is the problem
Older installations (rewireable fuses, no RCD protection, a board that’s been added to over the years) make fault-finding harder and give you less protection while the fault persists. If your consumer unit predates modern RCD protection, a consumer unit upgrade is often the single best improvement you can make to the safety of the whole installation.
Fault finding is one of the work categories on DD Electrical’s TrustMark listing. If your electrics are tripping anywhere around Dundee and the surrounding towns, tell us what’s happening. The more detail, the faster it gets found.