A tripping breaker is a working breaker. It is interrupting a circuit because something on it is drawing too much current, or because current is escaping where it should not. There are three underlying causes — overload, short circuit and ground fault — and only the first is reasonable to investigate yourself.
Never hold a breaker in the on position, wedge it, or replace it with one of a higher rating to stop it tripping. The breaker is sized to protect the cable behind the wall. Fitting a larger one means the cable overheats before the breaker reacts — which is precisely how electrical fires start.
The three causes
| Type | What is happening | Typical pattern |
|---|---|---|
| Overload | More current drawn than the circuit is rated for | Trips after several minutes, usually when a heavy appliance starts |
| Short circuit | Live conductor touching neutral directly | Trips instantly and hard, sometimes with a bang or scorch marks |
| Ground fault | Current escaping to earth | Trips instantly, often in damp locations — bathrooms, kitchens, outdoors |
| Failed breaker | The device itself has weakened | Trips at well below its rated load, or feels loose and warm |
Diagnosing an overload
Overload is by far the most common, and it is the one you can sensibly narrow down yourself.
- Note what was running
Write down every appliance that was on when it tripped. A kettle, a microwave, a toaster and a heater on one kitchen circuit will exceed most domestic ratings comfortably.
- Unplug everything on that circuit
Work out which sockets and lights are dead, and unplug all of them. Then reset the breaker. If it holds with nothing connected, you are dealing with a load problem rather than a wiring fault.
- Reintroduce loads one at a time
Plug items back in one by one, leaving a few minutes between each. The item that trips it — or the combination that does — is your answer.
- Redistribute or reduce the load
Move high-draw appliances to different circuits. Space heaters, kettles, tumble dryers, microwaves and air conditioners should each really have room of their own rather than sharing with other heavy loads.
- Watch for a single appliance at fault
If one specific appliance trips the breaker every time regardless of what else is on, that appliance has developed a fault. Stop using it and have it inspected or replaced.
Short circuits and ground faults
These are different in character. A short circuit trips the breaker instantly and forcefully, and may be accompanied by a bang, a flash, a burning smell or blackening around a socket or switch. A ground fault means current is finding a path to earth — often through moisture, damaged insulation or a failing appliance.
Both indicate a wiring or equipment fault rather than simply too much demand. If you see or smell any of the following, switch the circuit off and leave it off:
- scorch marks, discolouration or melted plastic at a socket, switch or in the consumer unit;
- a burning or “hot plastic” smell;
- buzzing, crackling or sizzling from a socket, switch or the board;
- a socket or switch plate that is warm to the touch;
- anyone receiving a shock or tingle from an appliance or fitting.
AFCI and GFCI nuisance tripping
Arc-fault and ground-fault devices are more sensitive than standard breakers, and they sometimes trip on equipment that is not actually dangerous — certain motors, older power tools and some LED drivers are common culprits. It is tempting to write every trip off as a nuisance.
Resist that. These devices are fitted specifically to catch the faults that standard breakers miss. Repeated tripping should be investigated and confirmed as a genuine compatibility issue by an electrician, not assumed to be one.
When to call an electrician
Call a licensed electrician if the breaker trips with everything unplugged, if it trips instantly every time you reset it, if you find any of the warning signs listed above, or if the breaker itself is warm, loose or will not reset. Work inside a consumer unit or on fixed wiring is restricted to qualified electricians in most jurisdictions — and for good reason.
Removing the cover of a consumer unit or distribution board exposes live busbars that remain energised even with every breaker switched off. This is not a DIY inspection.
