The residual current device (RCD) is the most important protection in your distribution board. It measures whether current is "leaking", for example through a faulty appliance or through a person, and then switches off in a fraction of a second. If it keeps tripping, there is a leak. Do not ignore it.
Common causes
- A faulty appliance: often one with a heating element, such as a washing machine, tumble dryer, dishwasher, oven or water heater.
- Moisture: water in an outdoor socket, garden lighting or a junction box.
- Damaged wiring: for example after drilling into a wall.
- Too many appliances on one RCD: every appliance leaks a tiny amount; together that can become too much.
- A worn RCD: an RCD can fail too.
Tracking it down safely yourself
- Unplug all appliances.
- Switch the RCD back on.
- Plug the appliances back in one by one. If the RCD trips with a particular appliance, you have found the culprit.
Does the RCD trip with no appliances plugged in, or can you not switch it back on? Then the problem is in the fixed installation. Leave that to an electrician.
Test your RCD
Press the test button on your RCD regularly. If it does not trip, have it replaced.
Can’t figure it out? Read more about repairs and faults or get in touch.
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