What to Do When a Circuit Breaker Keeps Tripping

Start With Safety, Not the Reset Button

A circuit breaker that keeps tripping is not being awkward — it is doing exactly what it was designed to do. It has detected an overload, a short circuit or a leakage of current to earth, and it has cut the power before anything overheats or catches fire. So the first rule is simple: reset it once. If it trips again straight away, or within a few minutes, stop resetting it and start investigating.

There are situations where you should not investigate at all. If the consumer unit feels hot, smells of burning, shows scorch marks, or if you can hear crackling, leave the affected circuit switched off and call a registered electrician. The same applies if anyone has had a shock or felt a tingle from an appliance or a tap. Those are not DIY problems.

Note What Was Running When It Tripped

Half the battle is working out whether the trip is tied to a particular appliance, a particular time of day, or a particular combination of things running at once. Before you touch anything, ask yourself what was happening. Was the kettle on? Had the tumble dryer just begun its heating cycle? Was the immersion heater running? A trip that only happens when the oven and the dishwasher are both going tells you something quite different from a trip that happens out of the blue at two in the morning.

Write it down, even just on your phone. Three or four entries on a notepad will often reveal a pattern that memory alone would miss.

Unplug Everything, Then Add Things Back One at a Time

This is the reliable method, and it takes about twenty minutes. Find the breaker that has tripped — usually labelled in the consumer unit as "sockets", "downstairs sockets", "kitchen" or similar — and switch it firmly to the off position.

• Unplug every appliance on that circuit. Not just switched off at the socket — actually pull the plugs out. Some appliances still leak current to earth when switched off at the wall.
• Reset the breaker. If it holds with everything unplugged, the fixed wiring is probably fine and the fault lies with one of the appliances you removed.
• Plug items back in one at a time, switching each on and letting it run for a few minutes before moving to the next. Start with low-draw items such as lamps and phone chargers, then work up to the hungry ones — kettles, washing machines, tumble dryers, irons, heaters and dishwashers.
• When the breaker trips, you have found your culprit. Unplug it, reset the breaker and leave that appliance out of use until it has been checked.

Remember that extension leads and multi-way adaptors count as part of the circuit. An overloaded four-way adaptor feeding a heater, a hairdryer and a games console is a very common cause of nuisance tripping, so unplug those too rather than assuming the fault is in the appliance itself.

Understanding What the Device Is Telling You

Not everything in a consumer unit is a circuit breaker, and the distinction matters. A miniature circuit breaker (MCB) protects one circuit against overload and short circuits. A residual current device (RCD) watches a group of circuits for current leaking to earth — the sort of fault caused by damaged cable insulation, water ingress or a damp appliance. Many modern units use RCBOs, which combine both jobs in a single device.

If a single MCB trips, you are usually looking at too much load on one circuit or a faulty appliance on that circuit. If an RCD trips and takes several circuits down with it, the cause is more often moisture or an earth fault — a garden socket that has filled with rain, an outdoor light with a cracked seal, or a washing machine with a damp element. Unplugging is still the right first move, but it is worth checking outside sockets and anything in a garage, shed or conservatory after wet weather.

Overload or Genuine Fault?

Overload is the friendlier of the two. It means the circuit is carrying more current than it is rated for, and it usually happens when several high-powered appliances share one circuit. The fix is a mix of common sense and, sometimes, small changes: spreading the load, not running the tumble dryer and the dishwasher at the same time, replacing a tired extension lead, or asking an electrician whether a dedicated circuit would suit a heavy-draw appliance such as a shower, an induction hob or a tumble dryer.

A genuine fault is different. If the breaker trips with almost nothing plugged in, if it trips the moment you reset it, or if it trips when a particular appliance is connected but not even switched on, that points to a short circuit or an earth fault in the wiring or the appliance. Old rubber-insulated cable, cable damaged by a nail or screw, rodent damage and water getting into back boxes are all common findings. None of these will fix themselves with another reset.

When to Call a Registered Electrician

Call someone if the breaker will not reset at all, if it trips repeatedly with nothing plugged in, if you have found damaged cable or a burning smell, or if you simply cannot track down the cause after working through the steps above. Electrical work in the UK is regulated for good reason, and an electrician registered on a competent person scheme can test circuits properly, confirm whether the fault lies in the fixed wiring or in an appliance, and certify any remedial work.

In the meantime, keep the affected circuit switched off, use sockets on other circuits sensibly, and do not be tempted to tape a breaker up or swap it for a higher-rated one. A breaker that keeps tripping is the cheapest safety device you own — and it is telling you something worth hearing.