A circuit breaker that trips is not the problem. It is the warning. Breakers and RCDs are designed to cut the power the moment something unsafe happens on a circuit, before cables overheat or someone gets a shock. When a breaker trips once after a storm or when too many appliances run together, it is usually nothing to worry about. When it trips again and again, it is telling you something needs attention.
Why breakers trip: the three common causes
1. An overloaded circuit
Every circuit is designed for a maximum current. Running a kettle, microwave, iron and heater on the same kitchen circuit can push it past that limit. The breaker trips after a few seconds or minutes, usually when the last appliance is switched on. Spreading heavy loads across different circuits often solves it, but if it happens regularly, the circuit layout may no longer match how you use the space.
2. A faulty appliance
Appliances with damaged heating elements, worn cables or water inside them can leak current to earth or short internally. A classic sign is an RCD that trips the instant one particular appliance is plugged in or switched on. Washing machines, kettles, water heaters and outdoor equipment are frequent culprits.
3. A wiring fault
Damaged insulation, a loose terminal, a nail through a cable or moisture in a junction box can cause a short circuit or earth fault inside the walls. These faults are not fixed by unplugging things, and they are the ones that need professional testing.
A safe step-by-step check you can do
- Switch off and unplug everything on the affected circuit.
- Reset the breaker or RCD once.
- If it holds, plug appliances back in one at a time, waiting a minute between each.
- If it trips when a specific appliance is connected, stop using that appliance and have it checked or replaced.
- If it trips immediately with nothing plugged in, leave it off. The fault is in the fixed wiring.
Never hold a breaker in the on position, tape it, or swap it for a higher rating. The breaker is sized to protect the cable. A larger breaker lets the cable overheat without tripping, which is how electrical fires start.
When to call an electrician
- The breaker trips instantly with nothing connected.
- You notice a burning smell, scorch marks or heat at sockets, switches or the board.
- The trip happens at random times with no obvious pattern.
- Lights flicker or dim before the trip.
- The RCD trips in wet weather, pointing to water in outdoor fittings or cables.
An electrician will test insulation resistance and continuity on each circuit, isolate the fault and repair it properly. If the circuit is simply overloaded, the right fix may be a new dedicated circuit or a board upgrade rather than repeated resets.
Breaker still tripping? Our electricians are on call 24/7. Book a repair or call 01915-491405. You can also read more about our panel and breaker upgrades.