Trip switch keeps tripping: how to find the cause

A trip switch is doing its job. Let's find why.

The answer in 2 lines. Look at your consumer unit and note which switch has tripped: the main switch, an RCD (a switch with a "T" test button) or a single circuit breaker (MCB). Burning smell, heat, crackling or water near it: touch nothing. Otherwise, with dry hands, unplug everything on that circuit and reset once. If it trips again with nothing plugged in, the fault is in the wiring or a fixed appliance (immersion heater, cooker, shower): call a registered electrician. If it trips when you plug one appliance back in, that appliance is the problem.

The first 3 steps

Dry hands, no burning smell, no water: look at the consumer unit without opening it, and note which switch is down and what was running.
Unplug the appliances on that circuit and switch off large appliances.
Reset once. If it holds, plug appliances back in one at a time, waiting a little between each: the one that trips it is the culprit. If it trips again straight away, leave it off and call a registered electrician.

Stop: danger

Burning smell, scorch marks, crackling, a hot consumer unit or socket, or a missing cover: touch nothing, do not reset. Smoke or flames: get out and call 999.
Consumer unit, socket or floor wet (leak, flood): do not reset. Have a registered electrician check before the power goes back on.
Never open the consumer unit, tape a switch up, or swap a breaker for a bigger one. It is there to protect you.
Someone has had an electric shock: do not touch them until the power is off; call 999. See our electric shock guide.

What tripped, and what it usually means

The main switch: the whole home is off. Often linked to an RCD or a serious fault; it does not usually trip on its own.
An RCD (marked "30mA", with a test button): several circuits are off. It detects current leaking to earth: a faulty appliance (washing machine, kettle, immersion heater), damp in an outside socket or light, or a wiring fault.
A single circuit breaker (MCB): one circuit is off. Usually too many appliances on that circuit at once, or a faulty appliance or bulb.
Older fuse boxes with rewirable fuses: a blown fuse wire. Have a registered electrician look at an old installation rather than rewiring fuses yourself.

What you can do yourself, and where to stop

Find the appliance by plugging back in one by one, then leave it unplugged and have it repaired or replaced.
Spread the load: do not run the kettle, oven, tumble dryer and heater on the same circuit at the same time.
Stop there if it trips with nothing plugged in, trips every time it rains, a circuit will not reset, there is a smell or heat, or after a leak or flood: call a registered electrician.

What not to do

Resetting again and again: a switch that keeps tripping is warning you of a fault.
Plugging extension leads into other extension leads.
Replacing a circuit breaker with a higher-rated one so it stops tripping.

Who pays and who to call

Registered electrician: look for one registered with a government-approved scheme. They can test the installation and find the fault.
Nothing has tripped and the street is dark: call 105, the free power cut number.
If you rent: the landlord must keep the electrical wiring in repair. In England, private landlords must have the electrical installation inspected and tested by a qualified person at least every five years (Electrical Safety Standards Regulations 2020), and this duty has now been extended to social landlords (councils and housing associations). Report the problem to your landlord in writing.

Good to know

Press the test button on each RCD regularly, as the label on your consumer unit says (often every three months): it should trip, then reset. If it does not trip, have it checked.
Label the circuits (kitchen, upstairs sockets, lights) so you know straight away what has tripped.
The rules for rented homes differ in Scotland, Wales and Northern Ireland; the safety steps are the same.

In Birmingham, Priya loses the kitchen and bathroom sockets every time the washing machine heats up. At the consumer unit, an RCD has tripped. She unplugs the washing machine and resets: everything holds. The next day she plugs the other appliances back one by one with no problem. The repairer finds a faulty heating element in the machine; the wiring was fine.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 18 October 2026, for England. Confidence: high for the safety steps and the roles of RCDs and circuit breakers, and the five-year inspection rule for rented homes in England; medium for how often to test an RCD (follow the label on your consumer unit). This guide describes common cases, not a diagnosis.