You should check if any of the switches on your circuit breaker/fuse box are turned off.
If you had just plugged an appliance in when the electric went off you can unplug that appliance then try to put all of the switches to the correct position in your circuit breaker/fuse box.
If you werent using an appliance you will need to unplug all appliances and then put all of the switches to the correct position before plugging the appliances back in one at a time. When the power goes off you will know which appliance has a fault. If the power will not go back on with all appliances unplugged please call us on 0300 373 3000.