What do I do when the electrics trip?

A tripped breaker is a safety device doing its job, not a fault in itself. The useful question is what caused it, and the answer is usually one faulty appliance. The isolation process below finds it in about fifteen minutes without any tools.

Safety

What you'll need

• Torch
• List of what's on each circuit (optional)

Step by step

1. Find the consumer unit — usually near the front door, under the stairs or in a cupboard.Take a torch. If the power is off, it will be dark exactly where you need to see.
2. Look for a switch in the down or middle position.Modern units have individual breakers per circuit plus one or two RCDs covering groups of circuits.
3. Note whether it's a single circuit breaker or an RCD that's tripped.A single breaker means an overload or fault on that circuit. An RCD means an earth leakage fault, which is more serious.
4. Unplug everything on the affected circuit before resetting.Lights, appliances, chargers. This is what lets you isolate the cause afterwards.
5. Push the switch fully down and then firmly up to reset it.Some need a definite off before they'll go back on.
6. If it stays on, plug appliances back in one at a time, waiting a moment between each.When it trips again, the last thing you plugged in is the fault. Leave it unplugged.
7. If it trips immediately with nothing plugged in, stop.That's a fault in the fixed wiring, not an appliance. Call a qualified electrician.
8. Once you've identified a faulty appliance, don't use it until it's repaired or replaced.It has an earth or insulation fault, which is a shock risk.
9. Label the circuits in the consumer unit while you're there.Ten minutes now saves a lot of guessing next time. Most units have blank labels nobody filled in.

Tips

• Kettles, toasters, washing machines and outdoor equipment are the most common causes of nuisance RCD trips, often from moisture.
• An RCD that trips during heavy rain or after using an outdoor socket usually points at water ingress somewhere outside.
• Test RCDs every six months using the test button on the unit. It should trip instantly; if it doesn't, get it checked.
• Keep a torch near the consumer unit. It's exactly where you need one and exactly where nobody has one.

Common mistakes

• Repeatedly resetting a breaker that keeps tripping — It's protecting against a real fault. Repeated resetting doesn't fix anything and can be dangerous.
• Resetting without unplugging first — It may trip immediately again, and you learn nothing about the cause.
• Working inside the consumer unit — There are live parts inside even with the main switch off. This is qualified-electrician work.
• Continuing to use an appliance that trips the RCD — It has an earth leakage fault, which is a genuine electric shock risk.

Questions people ask