Why do my electrics keep tripping?

First, identify which device has operated

A circuit breaker usually protects one named circuit against overload and short circuit. An RCD may protect a group of circuits against current leaking to earth. An RCBO combines both functions for one circuit. The labels on the consumer unit should show which part of the installation has been disconnected.

Do not remove the consumer unit cover. Note the label beside the switch and what was running at the time. If several circuits are off, an RCD may have operated even though the fault started with one appliance or one circuit.

A faulty appliance or flexible lead

Kettles, washing machines, dishwashers, irons, outdoor tools and extension leads are common sources of intermittent faults. Moisture, damaged heating elements and crushed cables can cause a device to trip only at a particular point in its cycle.

If there is no burning smell, damage, water or other sign of danger, unplug portable appliances on the affected circuit before attempting one reset. Reconnect them one at a time only if the circuit remains stable. Stop if the fault returns, and do not continue using the suspected appliance.

Too much load on one circuit

An overloaded circuit draws more current than its protective device permits. This can happen when several high-power heaters, cooking appliances or other loads share a circuit, especially through extension leads.

Overload tends to operate the circuit breaker after the load has been present, while a direct short circuit may cause immediate operation. Do not replace the breaker with a higher rating or keep moving the load to unverified adaptors. The circuit and intended use need assessment.

Water, outdoor equipment and damp

Outdoor sockets, lights, pond pumps and cables can develop faults after rain or physical damage. Water leaks into indoor accessories can have the same effect. The RCD or RCBO may trip even when the fitting looks dry from outside.

Do not open wet equipment or repeatedly re-energise it. Isolate the affected circuit if this can be done safely and arrange inspection. Damaged seals, cable entries and enclosures may need replacement, followed by electrical testing before the circuit returns to service.

A fault in the fixed wiring

Loose connections, trapped cables, deteriorated insulation, incorrect alterations and faults at accessories can all cause tripping. Problems may appear after drilling, a water leak, building work or the installation of new equipment, but some develop gradually.

An electrician isolates sections of the circuit and uses test instruments to narrow down the fault. Guessing and replacing random accessories can waste time and leave the underlying defect in place.

Can I reset the switch?

One reset may be reasonable only when there are no danger signs and you have safely disconnected a likely faulty portable appliance. Move the switch fully to the off position before returning it to on, as some devices do not reset directly from the middle position.

Do not keep resetting a device that trips again. Never hold it on, tape it in position or bypass it. Protective devices are designed to disconnect a fault before it causes greater harm.

• Stop immediately if there is heat, smoke, a burning smell, buzzing or visible damage.
• Keep clear if water may be in contact with electrical equipment.
• Do not remove covers or touch exposed conductors.
• Record which device trips and what was operating at the time.
• Arrange fault finding when the cause is not a clearly defective unplugged appliance.

What the electrician will test

The investigation starts with the pattern of the fault and a visual inspection. Testing may include insulation resistance, continuity, polarity, RCD operation and checks of connected equipment. Sections are isolated methodically until the defective part is identified.

Intermittent faults can take longer because the installation may appear normal between events. Notes, photographs, weather conditions and the exact appliance cycle can all help reproduce the problem safely.