Before changing a fuse or replacing a fuse wire, correct whatever fault caused the fuse to blow in the first place.
Switch off the mains socket outlet and remove the plug.
Unscrew the retaining screw on the underside of the plug between the pins. Remove the cover and lift out the fuse.
Note what rating the fuse is. It is always sensible to double check that the fuse is of the rating required for the appliance. If in doubt, check the instructions for the appliance or ask the manufacturer. As a general rule, use a 3 amp fuse for appliances up to 720 watts and a 13 amp for appliances from 720 watts to 3000 watts.
Fit the replacement fuse in the holder, check that all the conductors are securely held in their terminals with no stray strands of wire, check that the flex is held firmly in its clamp and replace the cover with its retaining screw.
When a fuse ‘blows’ on one of the circuits in your house, it is an indication something is wrong, so you will need to determine the cause and rectify it first. This is particularly important now that MCBs (miniature circuit breakers) are commonly used. The temptation is to simply reset it without identifying the cause.
Make sure the main switch is off before removing the cover of the consumer unit
Identify the type of fuse fitted. Hopefully, your unit will have been labelled to make identification of the individual circuits easy. If not, you will need to check each fuse. Fuses are labelled to show the rating in amps so you should be able to narrow down the possibilities by checking fuses of the appropriate rating for the circuit which has failed. These are set out on the continuation of this page.
Overloading of circuits
If you suspect overloading of the circuit,
make sure the main switch is still off at the consumer unit, remove the fuse and keep it with you to prevent the power being restored inadvertantly by others.
Unplug all appliances on the circuit which has blown. If the problem was overloading, once you have replaced the fuse or reset the MCB, the circuit should work. Otherwise, further investigation is needed.
Make sure the mains is still switched off and again, keep the fuse with you.
Check each fitting on the circuit by removing its cover to see if any of the wires have become loose or are damaged in any way. If this is the case, resecure or repair before refitting the covers of all fittings.
If you cannot identify the problem, seek the help of a qualified electrician.