Why does the trip switch keep going off?
An RCD trips when electricity is leaking somewhere it should not go, often through damp, damaged cable or a failing appliance. It is doing its job. The task is to find which circuit carries the fault, not to hold the switch on.
How do you find the faulty circuit safely?
Switch every individual circuit breaker on the board off, then reset the RCD. Now turn the breakers back on one at a time, pausing between each. When the RCD trips, the last breaker you touched feeds the faulty circuit.
Leave that breaker off and reset the rest. The house runs normally minus one circuit. If the faulty circuit is sockets, unplug everything on it and repeat. A single appliance is often the culprit, kettles and washing machines lead the league table.
When should you stop and call an electrician?
Stop if the RCD trips with every breaker off, if it will not reset at all, if anything smells hot, or if water has been anywhere near the board or the sockets. Those faults sit in the fixed wiring and need proper test equipment.
Stop too if you simply do not feel confident. Nobody sensible pokes at a live board at 2am.
What will we do when we arrive?
We test each circuit with proper instruments, find the leak and either repair it there and then or isolate it safely with a fixed quote for the repair. Read more about tripping circuits and fuse board faults.
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