Why Won't My Safety Switch Turn Back On?

Obviously, there are a number of variables, but in most situations, the cause of a tripping RCD is simply a faulty appliance or light fitting. 

As with any problem, the first step is gathering clues for yourself or your future electrician, if necessary. Questions to ask include: Has it been raining recently? Has this problem occurred before? Have you completed any electrical work on your property lately? Have you recently smelled anything burning, or has something been flickering that wasn’t a problem before?

Try to determine what is on the RCD that won’t reset. Is it all the PowerPoints? Just some of the PowerPoints? Is it lights or just PowerPoints? Go around the home checking what still works and what doesn’t. These clues usually narrow the issue from a whole house to potentially just a few areas, or even a few powerpoints.

In many instances, larger RCDs (such as the 2 and 4-pole Hager ones in the images) protect multiple circuits at a time. One of the first things that we do during late-night emergency attendance is isolate all the circuits (flick the circuit breakers down) and try to reset the troublesome device. If the RCD resets, flick the breakers back on one by one until the device trips off again. If you find one that trips it, you’ve usually found your issue and narrowed it down considerably. In doing this, you may even find that you have some power rather than none. Leave the problematic circuit off and turn all the others back on.

Once you’ve identified the faulty circuit, attempt to disconnect/turn off as much from that circuit as possible. Just remember, if it works, it’s not going to be causing the issue if the circuit is off! Switch off lights that aren’t working, and unplug all PowerPoints (don’t forget or try to exclude those hard-to-reach ones!)

Below, we’ve listed five essential appliances that people tend to forget when unplugging them: