Resetting a trip switch

square D type consumer unit Crabtree type consumer unit

General advice

Modern electric circuits are fitted with a circuit breaker fuse system. If a fault develops, a switch is tripped and the circuit is broken.
All of the fuses and trip switches are in the consumer unit. This is usually next to the electricity meter.
Trip switches usually operate because:
- too many appliances are being used at the same time;
- an appliance is faulty or misused;
- a kettle has been over-filled;
- a toaster hasn't been cleaned;
- a light bulb has blown; or
- an immersion heater is faulty.
If an appliance is faulty, leave it unplugged and get a qualified electrician or service engineer to check it.
If a wall or ceiling light is faulty, keep it switched off (put some tape over the switch) and contact us.

Open the cover on the consumer unit so you can see the trip switches.
Check which switches have tripped to the 'Off' position.
Put these switches back to 'On' position. On square-D consumer units, press the 'tripped' switch down until you hear a click before flicking it up again.

If the trip goes again, you probably have a faulty appliance. To identify the problem appliance:

note which set of lights or sockets (circuit) is not working;
unplug all appliances on that circuit, switch off the immersion heater and also switch off the MCB (and RCD, if appropriate) at the consumer unit;
switch the 'tripped' switch to 'On' position; and
plug in appliances and switch on lights one at a time until it trips again. Do not use double adaptors. Test one appliance on each socket until the trip goes.