Breaker keeps tripping: finding the cause and fixing it

In French, people still say les plombs sautent — "the lead has gone" — a leftover from the days of fuses, where a lead wire melted to cut the current. Fuses have disappeared from modern panels, but the phrase stayed. Today it's breakers that trip. The good news is that they reset — and above all, they're telling you something. A device that cuts out is doing exactly its job: protecting you from a fault. The whole question is which one.

What to do, in order

Start by looking at which device moved in the panel. It's the single most useful piece of information, and it points the way for everything else:

• One small module in the down position: that's a branch breaker. Only one area of the home is affected.
• A wider module marked 30 mA: that's a residual-current device. Several circuits go out at once.
• The large unit next to the meter: that's the main service breaker. The whole home is off.
• Nothing moved and everything is dark: check with neighbours or in the stairwell. If the building is out, it's the network, and Enedis is who to notify.

Then comes the isolation method. If it's a branch breaker: unplug the appliances in that area, reset it, then plug them back in one at a time. Whichever one trips it again is your culprit.

If it's the residual-current device, work the other way round: switch off all the breakers below it, reset the RCD, then raise the breakers one by one. The one that makes it trip again identifies the faulty circuit. Within ten minutes you know which room or appliance is involved — and if you then call us, that information genuinely shortens the diagnosis.

Two safety reflexes, though. Never force a device that refuses to reset, and don't hold it in the up position: if it drops back, a fault is still present. And never swap a breaker for a higher rating to "make it hold" — the rating matches the cable size, and fitting a bigger one means letting a wire heat up unprotected. It's a classic cause of fire.

The four possible causes

Overload

Too many appliances drawing on the same circuit at once: kettle, microwave and toaster together on the kitchen sockets. The breaker heats up, then cuts. It resets without trouble after a few seconds. If it happens regularly, the circuit is undersized for how you use it — a dedicated circuit solves it for good.

Short circuit

Live and neutral come into contact. The cut is immediate and sharp, often at the exact moment you switch something on. Usual suspects: a crushed extension lead, a lamp holder in poor condition, an appliance with a damaged cord.

Earth leakage

Part of the current escapes to earth instead of returning through the neutral. Detecting that is the 30 mA device's job, which is why it cuts several circuits at once. The usual culprits are appliances that mix water and electricity: washing machine, dishwasher, or a water heater with a scaled or pierced element.

Worn hardware

A breaker has a service life. After years of tripping, some end up cutting out for no real fault downstream. It's common on older panels, and it's a diagnosis reached by elimination.

What the timing tells you

The context is often more revealing than the symptom itself.

If it trips every time you switch on one particular appliance, the cause is in that appliance, almost without exception. If you have to run several things together to trigger it, you're looking at an overload. If cuts happen in damp weather or right after a shower, look for earth leakage — bathroom, ventilation, water heater.

And here's a clue few people know: if the power trips at night when nobody is using anything, think of the water heater. It switches on during off-peak hours, often around two in the morning, and an element at the end of its life produces exactly that kind of night-time cut. We see this case regularly, and it confirms quickly. A water heater that has stopped working follows the same diagnostic logic.

Breaker or RCD: they don't protect the same thing

This is the distinction that makes sense of everything else, and it's rarely explained. The branch breaker protects the cables: it cuts when the current exceeds what the wire can carry, so it doesn't overheat. The residual-current device protects people: it compares the current going out with the current coming back, and cuts as soon as a 30 milliamp gap appears — because that gap means the current is going somewhere else, potentially through someone.

Put simply, a breaker tripping points to a question of load or wiring. An RCD tripping points to a leak, and deserves a real search for its source.

When the installation itself is the problem

Sometimes no appliance is at fault. The cuts keep coming because the installation is no longer suited to the use: circuits overloaded because they date from a time when far less was plugged in, no dedicated circuits for appliances, an ageing panel with no modern residual-current protection.

In that case, restoring power achieves nothing — the fault will return. That's the point to look at an electrical panel replacement, or a wider rework of the installation if the circuits themselves are involved.

When to call us

Call us if the fault survives the method above, if a device refuses to reset once everything is unplugged, if you notice a burning smell or heat at the panel, or simply if you'd rather not touch it — which is a perfectly reasonable choice.

We work across Paris and the inner suburbs within 24 to 48 hours, faster in the 15th where we're based. Callouts start at €132 incl. VAT, covering travel and the first half hour, and our rule is simple: if we don't find the fault, you're not charged for the callout.

You can look at our electrical troubleshooting pricing in detail, or get in touch directly. For everything else we handle, see the electrical troubleshooting page.