If your safety switch (RCD) won't reset or trips immediately after resetting, it's detecting a current leak — usually from a faulty appliance or damaged wiring. The safest approach is to unplug everything, reset the RCD, then plug appliances back in one at a time to identify the culprit. If the RCD trips with everything unplugged, you have a wiring fault that needs an electrician.
What to do right now
- 1
Unplug everything
Go through the house and unplug every appliance from every power point on the affected circuit. Include the fridge, washing machine, dishwasher, and anything hardwired with an isolator switch.
- 2
Reset the safety switch
With everything unplugged, try resetting the RCD at the switchboard. If it holds in the ON position, the fault is in one of your appliances — not the wiring.
- 3
Plug in appliances one at a time
Reconnect appliances one by one, waiting 10 seconds between each. When the RCD trips, the last appliance you plugged in is the faulty one. Leave it unplugged and reset the RCD.
- 4
Call an electrician if it still trips
If the RCD trips with nothing plugged in, the fault is in your wiring — likely moisture ingress, damaged cable, or a failed light fitting. This needs a licensed electrician to locate and repair.
When to call an emergency electrician
- ⚠️The RCD trips with everything unplugged — indicating a wiring fault
- ⚠️You can't identify which appliance is causing the trip
- ⚠️The RCD trips on the lighting circuit (you can't unplug lights)
- ⚠️Multiple safety switches are tripping at the same time
- ⚠️The RCD itself looks damaged, burnt, or won't physically click into position
- ⚠️The issue started after rain, flooding, or a storm
How much does it cost?
An electrician callout to diagnose an RCD fault typically costs $150–$350 during business hours. If a faulty appliance is the cause, there's no electrical work needed beyond diagnosis. Wiring faults cost $200–$600 to repair depending on location and access. RCD replacement costs $180–$400 per switch.